Like… if you open a coffee shop and run it for a while and it makes you happy but then stuff gets too expensive and stressful and you want to do something else so you close it, it’s a “failed” business. If you write a book or two, then decide that you don’t actually want to keep doing that, you’re a “failed” writer. If you marry someone, and that marriage is good for a while, and then stops working and you get divorced, it’s a “failed” marriage.

The only acceptable “win condition” is “you keep doing that thing forever”. A friendship that lasts for a few years but then its time is done and you move on is considered less valuable or not a “real” friendship. A hobby that you do for a while and then are done with is a “phase” - or, alternatively, a “pity” that you don’t do that thing any more. A fandom is “dying” because people have had a lot of fun with it but are now moving on to other things.