While I sympathize with your need, I don't think we'll see a new OS fill this space.
Firstly, there's the obvious "all the apps you run on it". Your new OS has no apps, and even if a few emerged no business really wants to commit to running on a new OS with only a couple apps.
I mean, if you want a stable OS there's always BSD, or BeOS or whatever. Which we ignore because, you know, Windows. (And I know it's fun to complain about ads on windows and Microsoft in general, but there's a reason they own the market.) OH, and business users don't see the things folk complain about anyway.
Personally I have utilities on windows that were last compiled over 20 years ago that still run fine.
Secondly no OS operates in a vacuum. You need to store data, (database) browse the web, communicate, secure traffic and so on. Those are very dynamic. And again (by far) the most stable place to run those things is Windows. Like Postgres 9, from 15 years ago, is still used in production.
Of course it's also possible to freeze any OS and apps at any time and it will "run forever " - or at least until the version of TLS supports dies.
So no, I don't believe there will be a new OS. Windows Phone died because there were no apps. Your new OS will have the same problem.