Cosmic is already more usable than most Window managers, that literally just manage Windows.
I mean, it has apps… and GUI settings…
There is a guy called Ryan Brue that packages all the COSMIC apps. He created a SIG and in the channel there are some COSMIC Devs helping out.
There is a uBlue variant with COSMIC, working pretty great.
COSMIC just breaks KDE Apps a bit. Will have to see if some package may fix them, as they are so themable that missing packages make them use aome shitty fallback theme.