This subreddit is for modernist art, roughly 1860-1980. Visual, written, audio, architecture, all of it is valid. It is not for contemporary art made after the modernist period.
Despite it being on the sidebar and the definition being the first stickied post, this subreddit still gets a post or two per day from people who either want to post their own bad art or something made after the 1980~ cutoff. There are plenty of subreddits for those things and plenty of movement-specific ones that don't bother removing contemporary art.
If you post these things, or god forbid the NFT spam, you're just out and won't get a second chance. This is an art history and theory subreddit more than it is "look at this pretty picture". It's not going back to that even if it means lower engagement because that content is shit. The subreddit will once again go to shit if people see it's already full of it.
Non-image posts like questions and discussions are still okay, either about modernism itself or contrasting it against earlier/later periods. There needs to be some connection to this very specific term, the 1860-1980~ historical era, and/or the movements and cultural trends in it though.