In some ways modern society is hard for people with ADHD: more jobs demand skills that can be hard to aquire for people who have a hard time sitting in a classroom.

In certain (but certainly not all IMO) other ways we are more tolerant towards especially kids these days: I never experienced it, but I still heard about[0] kids being punished with stick/cane in school, or even one particular headmaster who would use electrical shocks on kids.

These days are long gone now both here and were I grew up.

[0]: Skits, cartoons in magazines as well as stories.

For one example, my biggest impairments are definitely to a) general motivation, including non-work/school activities like reading a book I'm interested in (well-treated by medicine); general impulsivity, including emotional impulsivity and stimulation seeking behaviors (well-treated by medicine); and significant impairments to working memory (unfortunately not well-treated by medicine). The working memory is the real PITA. Studies show people with ADHD lack a specialized area of their brains for handling working memory, unlike non-ADHD people. This means that for me, my brain handles working memory tasks analogously to how blind people can learn to "see" with their tongues -- I have to marshal unrelated brain areas to try to make up the difference. (For an example of what this is like in practice, walking into a room and forgetting why I am there occurs at least a dozen times per day.) Another huge area of impact is to sleep; the vast majority (almost 90%) of adults with ADHD also qualify for a sleep disorder, usually delayed sleep phase.

As for jobs, actually one big risk tends to be having an emotional outburst at your boss or colleagues. Adults with undiagnosed ADHD usually end up developing a reputation for anger problems, as they have big difficulties controlling primal emotional responses. Another major area of challenge comes from our tendency towards substance abuse problems; many undiagnosed adults end up self-medicating via alcohol or street stimulants.

Anyways, I know this is kind of a big tangent from the OP, but I just wanted to throw that out there. I didn't get diagnosed until I was nearly 30 mainly because I was, in fact, able to sit in classrooms. I have an inattentive subtype, meaning it doesn't materialize as visible restlessness and hyperactivity as much as it does in others. Because I wasn't running around classrooms and acting out, I had to suffer in ignorance for decades.

I don't qualify as ADHD, but I've found that I do the same, substituting my auditory memory for working memory. Apparently it's much easier for me to keep a train of thought on the rails if I use my language processor for additional short-term storage. I didn't even realize I did this, until people started telling me that I shouldn't talk out loud during written exams.

This may be miles off from your experience, it just lit a spark of recognition.

You can do it sub vocally without making sound.

Quite possibly because the distinction between ADHD and ASD (among other disorders) is biologically dubious. See e.g. https://www.nature.com/articles/s41398-019-0631-2

> meaning that people with ADHD qualify as neurodiverse

Now this is a really big tangent, but the term "neurodiverse" annoys me. One of the reasons is, there is actually a great deal of genuine neural diversity among so-called "neurotypical" people. For example, while most right-handed people activate left hemisphere perisylvian regions in language processing, a small minority of right-handed people activate right hemisphere perisylvian regions instead. So that small minority are "neurodiverse" in a genuine physical sense, yet absent some clinically significant dysfunction (and this example of neurodiversity has no known clinical significance), nobody will call them that. (I owe this example to https://pubmed.ncbi.nlm.nih.gov/28130875/ who in turn cite it to https://pubmed.ncbi.nlm.nih.gov/10611122/ )

In reality, "neurotypical"-vs-"neurodiverse" is a clinical distinction, not a neuroscience one. People with (certain kinds of) clinically significant dysfunctions get the second label, people without those dysfunctions get the first. Very rarely does anyone actually look at what is going on in the brain (eg via MRI) before applying these labels. (There are studies claiming to find differences in the brain between the "neurotypical" group and various subsets of the "neurodiverse" group, but those studies tend to contradict each other, have problems with reproducibility, and only claim to find group differences not individual ones – there may be a statistically significant difference between the mean of some property in two groups, but the ranges of that property in the two groups will be overlapping.)

Don't underestimate my knowledge about ADHD ;-)

Also, much (most? all?) of what you write is correct but I don't feel it detracts from my point.