Because despite getting clobbered on desktop, Intel is still competitive in laptops and produces more than AMD can.
>Then the Ryzen one is old as well. Why not a new gen?
Because there's not enough supply.
>Why not trying ARM like Apple did?
Because people use Microsoft for backwards compatibility. They tried it before with Windows RT, and it was a flop.
https://www.microsoft.com/en-us/p/surface-pro-x/8qg3bmrhnwhk
They did. Several times. People turned their noses at them because they couldn't install outside of their app store or their garbage x86 apps directly. The models that did offer x86 compatibility over ARM performed poorly.
Apple can get away with segmentation because people will still buy Apple products because they're Apple products. Microsoft's own brand doesn't carry the same fashionable prestige, so minor annoyances on Macbooks become dealbreakers on Surface.
??? Apple gets away with it because their x86 -> ARM translation actually works. Without it the M1 Macs would be DOA.
Hopefully Windows will soon see an equally as effective x86 -> ARM translation layer.
Apple can get away with an on-the-fly architecture transition, because they're willing to invest a shit ton of resources, and also because Rosetta 2 is the software equivalent of the Top Gear opening theme played by Slash on a guitar that's on fire.