So your opinion is that it's ready?
But as far as I know that is this case. That Microsoft's offering is much stronger when it comes to large scale corporate deployments. Unless you want to make the claim that e.g. RedHat's offering is on par or better, which isn't something I have heard in the wild.
Now, does using Ubuntu cover some of these glaring warts? Perhaps. But that often opens its own set of problems. Each comes with its own set of workarounds. Where macOS and Windows excel, is their sense of "polish". Most happy path things just work, and work 99% of the time.
All that said, I'm die-hard Linux ALL THE WAY! I just couldn't say that it's ready for most purposes. For the things that I'd use a tablet for? Sure.