I don’t think that is necessarily out of the running yet. OS development is expensive and low profit. Commodification may be inevitable. Control of the shell and GUI, where they can push advertisements and shovelware and telemetry on you, that is profitable.
So in 20 years, 50? I predict proprietary OSes will die out eventually, balance of probability.
The cheaters and cheat developers will just move to Windows, and the legitimate Linux users will quit. I don’t see the upside, this doesn’t solve the problem.