Have a look here for the differences between 10 and 11: https://www.cnet.com/tech/computing/windows-11-vs-windows-10/
There are increased system requirements for 11, so an older machine that can run 10 may not be able to run 11: https://en.m.wikipedia.org/wiki/Windows_11
My personal view is that while security patches are essential, functional upgrades are a pain in the arse. For every new feature that you like, there will be two old features that you liked and have now been removed.
Unless you need something specific on the new version, it's not worth the effort.
In the sense Microsoft don't issue updates for XP any longer. By all means indulge your nostalgia for old computer games but i wouldn't recommend connecting to the internet on a computer using XP.Who let it die off? I was only using it a couple of days ago playing civ2.