Social media for the blind:
Bluesky, hardly any Alt Text. To understand an image, you must open the post, tap on the image and hope your screen reader can describe it, or spend a minute or so scanning it.
X, hardly any image descriptions. The built-in AI will try to describe the images which is a major improvement, but you need to wait until the screen reader finishes reading all the info about the post.
Mastodon, loads of image descriptions. What a pleasure it is to browse my timeline here.