I don't think it's quite a titanic enough endeavour to put slow in quotes. It's been in development for 16 years and only got a stable support for screenshots a few months ago. Does drag and drop work yet?
IMO at this point it is reasonable to say that the idea of having a shared protocol and then making every desktop environment implement the entire display server was not a good one. The Linux community does not have enough manpower to make that work well.
This doesn't make any sense. The only way to move around without depending on other companies is by walking, and there's no way that can replace cars, trains, buses, bicycles, etc.
Not depending on anyone else is not a sensible goal. We live in a society.