I can agree that challenging Steam is probably a good thing, but right now Steam just gives so much more value to Devs and publishers. Steam provides:
- a review system
- remote play
- the workshop
- discussion threads
- cards and the points store
and that's just what I can think of, not including the player specific stuff like library sharing.
Devs and publishers pay more, but get a community and ecosystem in return instead of just a platform.
There's no simple answer to that since games become inaccessible in different ways and with different severities. It'll always be an argument you have to make.