I think Element has the best chance of being a viable discord alternative. Especially with matrix 2 around the corner.
Element X (their new mobile app) loads as quickly as discord and supports e2e calls as well as chat.
It is a different app than discord though. It does not feature the nice server layout that discord is kind of known for but it is planned with spaces.
I say give Element another year or two and it will be a very formidable chat program.
And I have no doubt they are doing well financially and will continue to push improvements as matrix is very widely used. I mean hell apparently Nato uses it
Very excited about fractal 9. It's probably my favorite matrix chat application outside of element. I just wish it would support calls but that may be out of scope