[joeraut]

Great point on accessibility, a guarantee of screen reader support is a benefit that would be lost with screenshots or text without the correct semantics.

[aembleton]

I don't think it would be hard to grab the text along with the screenshot and set the alt text.

[rchaud]

Reddit seems to be able to do this. They have bots that transcribe the text on image-based memes, and the transcription has always been accurate.