Does Spanish assign gender to inanimate objects?

It assigns linguistic gender, which isn't the same as people's gender.

Yes, I thought so. Isn't that unnecessary overhead? I think this disqualifies Spanish and other languages like it.

To me, it doesn't matter much, because there isn't much "extra" to learn. The gender is derived from the word suffix, and there are three or four rules to that, so it's both extremely easy to learn and to apply to unknown words.

This is unlike, say, German, where each word has a random gender and you need to learn it along with the word. There, I agree, that's unnecessary overhead.

"They said" is good English, whereas in Spanish word endings change due to gender.

What is "he said" in Spanish, and what is "she said"?

My point is that, in English, it's possible to leave someone's gender entirely unstated, whereas in Spanish someone is either "el amigo" or "la amiga" with no other options.

Also, if you don't know Spanish, I'm not going to teach it to you.

It's only possible if you use neologisms like "they said", whereas in Spanish you can go entire sentences without referring to the gender.

Singular they goes back to the 1300s. Whatever it is, it is not neologistic.

https://en.wikipedia.org/wiki/Singular_they

I don't know, the sentence "by 2020 most style guides accepted the singular they as a personal pronoun" doesn't scream "it's been used like this for centuries" to me.

This is one of those things that's both true and false at the same time.

It's true it goes back to 1300, but it had also fallen out off fashion and was considered "wrong" later on. Languages change, and don't do so in a linear straight-forward way. From our perspective, it's very much a neologism (although it's been a few decades, and arguably already passed the neologism stage).