writing ALT text is, first and foremost, the right thing to do. like curbcuts, accessibility benefits everyone.
in addition to making media accessible to screen reader users, writing good ALT:
» Allows blocking or hiding posts if there are filtered keywords in the ALT
» Is translated along with body text, if your instance supports autotranslation
» Makes your posts searchable with any words in the ALT
» Lets people on low bandwidth connections decide if they want to load the media