> Are they going to ship an official cross platform UI library any time the next century?

So because they haven't produced your pet project means they haven't changed?

> Aren't almost all of their contributions for integration with their proprietary technology?

No. They didn't have to make .NET cross platform and run equally well on Linux, they didn't have to join the Linux foundation and make contributions to the Linux kernel. There are hundreds if not thousands of examples like this that would have been unthinkable under Gates and Balmer Microsoft.

> Windows 11 meanwhile makes me wait for them to add a robotic arm with a knife as hardware requirement, to improve the backstabbing experience.

Microsoft is much, much larger than just Windows. You seem to have a very limited understanding of everything they do.