But I found that even that was not easy to do with "traditional" OCR, notes here: https://digitalseams.com/blog/image-transcription-humbled-me
Alt text is not there to explain the joke, that would imply cripples are stupid.
AI is fine, if you want to go against the trillions $ come back with a proof.
LLMs fail, wow easy to find, I'll bet alt text on random internet images fails at over 10 times the rate, most are null.
Authors can often use an LLM to save time by outputting an initial draft an author can fix.
Readers can also use their own LLM as a supplement, to ask it questions about details in an image that wouldn't be in the alt text. LLMs will get things wrong but are generally good enough for such supplementary use.
Same with closed captioning!
And then the alt text Nazis can be quiet, too!