In isolation, yes, but when you're actually using this sentence there will be context. "When you want to onboard a new developer, they will require access."

"There's a new person joining the team." "What do we need?" "They require access to the stack."

Both are obviously singular they.

Ah got it! So the solution is pretty much to prefix a short sentence to provide context that indicates that they is going to be used in a non-standard way, so instead of:

"They are at the door right now, please open it asap"

You'd say:

"Someone is visiting, they are at the door right now, please open it asap"

This indeed does not sound unnatural or misleading to me anymore.

(I know you'd probably just rephrase the second sentence but this is just and example)

"They are at the door right now, please open it asap" requires no count. It is fundamentally unambiguous in its phrasing, it could be 1 person or 50.

"They are at the door right now, please open it asap [and let a singular individual in]". If that bracketed portion is the intent, requires context. It implies a specific individual who you could identify by name or by a gendered pronoun if known (and unique in context) or description. Either way, you need to let the person you're speaking to know which "they" of the potentially many individuals at the door you want to permit in.

This context may have already been supplied. For instance, on visiting an office for an interview a name will already be supplied and the person (security, admin) doing the opening may already know the identity and that it is a singular person who is expected. In which case, "they", because of prior context, is entirely unambiguous again.

I find the whole “semantically singular, grammatically plural they” thing fascinating because it brings into European languages (granted, English is a pretty unusual one) an idea that I previously only encountered during a brief foray into Japanese:

Most of the time, either the number of the noun is clear from context or you are completely fine not knowing what it is.

“They are waiting at the door for you.” Is there one of them? Is there more? Who cares, the sentence covers both!

Granted, Japanese has syntactic gadgets that enable you to add that information in a natural way in cases where you actually do care, but it’s still surprising at first how much communication works without obsessively marking every noun for number. How do Japanese, Chinese, and Korean speakers communicate without grammatical number? The same way Russian speakers communicate without grammatical definiteness, or English speakers communicate without grammatical perfectiveness, or all of them communicate without grammatical clusivity, etc.: either they mark it explicitly or—in most cases—they can perfectly well do without. It’s technically ambiguous, but only in the way every other word that isn’t marked for every grammatical category found across human languages (i.e. every single word) is ambiguous.

(In case you were wondering why speakers of Slavic languages sometimes tend to overuse “some” and “this” in English, that’s why: those are the way their native languages, lacking obligatory articles, mark nouns for definiteness when it actually matters; the overuse is what happens when you teach articles as “these weird formal words you have to use according to these weird formal rules” without telling your students that they actually bear meaning.)

"Semantically singular, grammatically plural" is already very common in English due to singular "you".

It's probably just my non-native context/semi-translation messing with my understanding, if someone told me "they are at the door" I'd be like "They!?"

Disclaimer: I'm not a native speaker.

Why "they requires access" isn't fine?

It looks grammatically incorrect but the ambiguity is removed thanks to the "s" particle.

English already has similar irregularities in other contexts which seem to bother nobody.

i.e the sentence "If I were you, I'd do X and Y". The word "were" looks weird there but it solves a problem. Can't we treat "they" as singular in a similar manner?

Singular they is like plural you in English. Without context it’s hard to determine the intended count because the verb is conjugated the same way regardless of count. Unlike, say, Spanish or most Romance languages.

This can introduce ambiguity, but declining to use ancient (800 years, why are we debating it still?) inclusive phrasing because some people fail to create context for their pronouns is silly.

> Why "they requires access" isn't fine?

It just isn't.

When I was learning French I quickly learnt not to question why something is right or wrong. It's wrong because the natives say it's wrong. It's as simple as that.

I totally understand and kind of sympathize with that.

I just feel (citation needed) that there are more non-native English speakers than native ones and natives' opinions is no longer enough.

Regardless of count of native and non-native speakers, singular they is still 800+ years old in English. It is ambiguous without context around the potential count and it's unlikely the conjugation rules will change in the next few years to accommodate this. However, in English (and I suspect most languages) it's generally not common (or it is discouraged) to drop in a pronoun without sufficient context to identify the individual or group that it describes, which also includes count. So even if the verb conjugation remains ambiguous (with a phrase or sentence taken out of context), in context it should make sense so long as the person is semi-competent in communicating.

"They need access" - no context, ambiguous.

"They need access" while pointing towards an individual, unambiguous; while pointing toward a group of new students on the first day of school, unambiguous.

"They need access" in an email as a single line or a subject with no message body, completely ambiguous and will elicit a response of "Who needs access?" If it's part of a prior conversation chain that the recipient can recall, they'll give access to however many individuals they are aware of be it one or one hundred because it's unambiguous in the context (for them, but not for us).

Perhaps worth mentioning that "you" is "ambiguous" in exactly the same way: it's grammatically and historically plural but can now refer to either a single person or a group.

French and German also use a grammatically/historically plural form for polite "you". But Italian seems to use a feminine third-person pronoun for that purpose ...

You is historically plural?

I knew it could be applied to a group in certain cases, but only when referring the group as a single unit, really still singular. Or when speaking one-to-many, where each recipient is meant to hear you to refer to themselves, though the speaker spoke to a group.

"you 12 come with me" is really still referring to a single unit to me, the group, not the individuals. IE, it conveys no more meaning than saying "you come with me" where the object might be either a person or a group equally.

It's interesting, I don't think English has a way to distinguish "me singular" vs "me a member of a plural", other than by adding other words like "you all"

That is a pretty interesting idea. I love the idea that someone starting out with the desire to project their will on the rest of the world, becomes so successfull that they no longer own their own language. "If you didn't want other people to mess up your language, maybe you shouldn't have insisted that everyone else speak it?"

Context. Or “the <descriptor>“, like “the user requires access”.

“The user can change settings by selecting properties. Once there, they can opt out of silly debates.”

Is there any ambiguity? Pronouns belong in places where an identity can be, well, identified. Not standalone. Sans context we don’t even know who “he” is. If it’s a real person and not a hypothetical person, use their gendered pronoun if desired.

“Jtsummers needs access. His credentials can be verified by…”

It's not more confusing than addressing your male or female cousin. Language isn't always helping, but using "they" for everybody just seems like a natural fit.

This scenario is for a specific person and you would most probably use their name or you would still use he or she or their pronoun in context.

"This person requires access"?

I’d need to see the preceding sentence but probably not.