"it's not an accessibility problem or a symptom of systemic ableism if the OP doesn't add the image description to the original post, people can just reblog it from you if they want to. Asking people to add the ID to their post is rude and self-absorbed"
the only people who think this way are ableists.
You know all the Mickey Mouse art I hurt my wrist frantically writing image descriptions for?
Yeah, a lot of it is being reblogged without any image description now with thousands of notes, because people only see the original post, they don't bother to check the notes to see that there's an ID right there that I took the time to write.
Tumblr encourages you to reblog a post as soon as you see it, and people who don't make a conscious effort to stop and try to be accessible do not take the time to stop and check the notes for an ID before rebloggging.
Adding an image description to your original post, and any important reblogs, is the most accessible thing you can do, second only to writing the post with an image description in the first place.
If you actually care about disabled people (or disabled people other than yourself and a select few family members), then when someone takes the time to write an image description for your art, add it to the original post or reblog. I don't care how many notes the post has, if you care about disabled people and care about accessibility, do it.
Especially if you're ablebodied. Many people have said it before me, but it's absolutely evil how most of the people on this site who write image descriptions are physically disabled, the people who have to put in the most amount of effort to do so, at the highest cost to ourselves.
It's been 4 days since I hurt my wrist typing so many image descriptions. It's probably going to continue hurting for another few days at best.
If you are physically abled and will not be put in literal physical pain from writing image descriptions, then you need to start writing them. It shouldn't always be left to disabled people to do all the heavy lifting for accessibility. If you call yourself a leftist or a communist or an anarchist but won't even write an image description for your art or memes or even edit it into your original post, then just stop pretending you care about disabled people, because you clearly don't.
See this post for tips on writing image descriptions.
If you do nothing else please start checking the notes for an image description before you reblog undescribed art. It's the absolute bare minimum.