Windows 11? Let's see here...

Spyware/malware since that infamous Windows 7 update sending everything (including passwords) to Microsoft. Ads spread across the UI in W11. Simple features hidden or disabled. Bing Internet search results in the Start Menu that can't be disabled unless you edit the registry. Search engine in the Start Menu cannot be changed. Numerous other previously simple settings changes that now require registry edits. Menu items gone, and others that still exist but inexplicably have been removed from the Start Menu search. Edge browser forced down your throat no matter what you set as the default browser. Upgrades that you can't do at your convenience and forced restarts that happen even if you have open files that you're editing. Long (sometimes really long) upgrade restart times. Forced Microsoft account use to install and use the OS & Internet access required to even install the OS. Absurdly inflexible hardware requirements that make no sense for most people. A taskbar that can't be moved. Numerous programs and garbage spread through the OS that cannot be removed or disabled.

Besides that, what's not to like?