linux is more usable today than ever before. The only chokehold that microsoft have on windows is legacy business apps, and office (and various compliance requirements for gov't software that opensource tend not to have, like FEDRAMP).

MacOS is gaining ground, but because their hardware is legitimately superior. I imagine commodity laptops to be a dying breed in a few more years.

Gaming on a windows PC is the last bastion that macs tend not to compete in at all, and on that front there's SteamOS.

Microsoft signed their own OS death warrant when they switched from being backward-compatibility oriented way back in the Vista days. It might take another 2 decades for it all to play out, but from what i can see, it's one straight road down to obsoletion.