You're downvoted but you're 100% correct.

It makes absolutely zero financial sense to create a new general purpose operating system.

That's billions of lines of code. With a B. And that's just the code - getting it to work with hardware?

Do YOU want to talk to 10,000 hardware vendors and get them on board? No! Nobody does! That's just money burning!

But, there are valid political reasons for creating a new general purpose OS.

It is a lot less if you are aiming to support a small set of platforms, don't need general driver support for everything possible accessory and peripheral under the sun, and if your file system usage is limited.

If you are building for a single abstraction, code gets much simpler, instead of building a platform that multiple abstractions can then be built on top of.

If you are China, the vendors are you and money is treated differently than in the west. Balance sheet will accommodate a project like that easily, especially if it decouples them from the US. They’ve already got their own software ecosystem which most people don’t hear about or heard once or twice, and it’s running their tech scene.