I have encountered more image descriptions on Mastodon in 24 hours than I have in Twitter in a couple of years. Seriously. I'm not exaggerating.
As a blind person, this means a lot to me. If you read this and you describe your images, thank you so, so, so much on behalf of all of us. If you don't, now you know you'll be helping random Internet strangers make sense of your posts by typing in a few more words than usual.