Every fanfiction is either fix-it or wish-fulfilment. I filtered them out from the main site because of that. If I want to read fanfiction, I will go to Ao3 or FFn.
Readers go to writing sites for the kind of stories they like. Smut for SH, LitRPG for RR. You don't have to fight for visibility...
That's not stagnation. You still get new readers. The number don't increase because some of your readers deleted their account or got banned. Some even might be no longer interested in your story.
Your chapters length are too long. 40 chapters in my novel is 10 chapters in yours.
If you split your chapters into multiple shorter one, you can have 4x more views and readers. I don't think you care about statistics, though. Why else don't you promote your story? No wonder Tabula say it's...