I’ve generally worked in tech with rather educated people, but even there the lower portion of their writing skills can be disappointing.

I'm pretty sure that education helps. I used to hang out on /r/Europe, which had a lot of non-native English speakers...but who were generally very well educated (probably because of the sort of people who are going to be hanging out on an international forum and writing in some language that often isn't their native tongue). The quality of the writing was pretty darn good. I'd say that the Dutch users there in particular wrote exceptionally clean English.

That said, it was an interesting experience, because I discovered that there are completely different categories of errors that native and non-native speakers make. For example, I've seen plenty of native speakers here in the US confuse "their", "they're", and "there", probably because they learned to speak the terms long before they wrote them and then kind of mentally linked them in the interim. I virtually never saw that error on /r/Europe, probably because a lot of Europeans learned to write English relatively-early compared to learning to speak it. But I did see a higher proportion of people having problems with some errors that aren't common among native speakers:

• Words where English has one word that passed through different languages and then entered English as two different words (e.g. bloc and block).

• Headlines. Until spending time on that forum, I was basically oblivious to the fact that headlines in English use very different grammar, a different set of conventions, than standard English. I'd grown up reading them, internalized them, never thought about it. Then I wound up on a ton of posts with people in /r/Europe complaining that the submitted headline for an article was completely nonsensical or unreadable. To me, the headlines seemed completely reasonable; at first I thought that users were just joking. Took me a while to realize what was going on. I couldn't even find any websites that provided a full summary of all of the headline-specific grammatical conventions, just some that had some common examples.

• Words that have irregular prefixes. For example, someone might write "uncompatible" or "noncompatible" instead of "incompatible". English has many different prefixes that can mean approximately "not", ("a-", "un-", "anti-", "non-", "in-", "im-", "ir-", "ex-"). Just have to memorize them, kind of like grammatical gender in some other languages. I've rarely seen native speakers not know the right irregular prefix, but that was an extremely-common error to see on /r/Europe.

• Specifically for Slavic language users, I saw some users having trouble with definite/indefinite articles (something that doesn't exist in Slavic languages and is actually fairly uncommon in languages globally) or using gendered pronouns where one wouldn't in English (modern English has only the tiniest remaining vestiges of grammatical gender).

Also, it was interesting to see where errors did crop up

my impression was that it tended to be with French or maybe Spanish speakers. My guess is that that's because those languages are the other European languages that are also (relatively) widely-spoken around the world, and so by using English, you expand the pool of people you can talk to the least; I'd guess that people who speak these other languages use English less. For Spanish, it's maybe a factor of 3. For French, maybe a factor of 5. Compare to something like Icelandic, where it's something like a factor of 4,000.

ChatGPT also dramatically worsens the problem.

It just does the writing and reading for you.

So you then just... never develop any actual reading or writing skills.

Its turning people into something akin to zombies, more or less. Either that or maybe just trying to think of it as some new kind of addiction or mental disability would be a more apt comparison?

I... its baffling, I can barely comprehend how significant and widespread this problem is... when I was in elementary school, I finished assignments and such so fast, with such frequency, that I would get assigned to go out into the hallway and help other kids who were struggling with reading skills, I'd help them read through books, sound out words, explain what they mean.

Thats my point of reference here, I'm back in 2nd grade, helping (probably dyslexic) 4th graders learn how to read.