The KDE plasma UI feels like all the best parts of windows 10 to me. The default taskbar+clock+system tray+start menu UI feels exactly like windows 10 to me. But you can also customize it very easily. The settings menu feels a bit more like MacOS than windows’ control panel though.
Several linux distros use that UI. Im on NixOS but i probably wouldn’t recommend that as a starting place. I’ve used bazzite and it worked pretty well out of the box. But i think there’s ubuntu and debian variants that use plasma that are probably pretty good as well.
The recommendation for the average inexperienced user trying out Linux for the first time should be Kubuntu. Full stop. Saying this as an Arch and Gentoo user.
Yup, Plasma has also gotten really good. It started to get really good with 5 and has polished like crazy with 6. It's defaults are now pretty close to perfect out of the box for me as a long time windows user.
I'd say it's close to the windows 7 or 10 experience. But without any of the clutter that has crept in.