KDE has pretty much always aimed (intentional or not) to beWindowsish in its interface, integrations, shortcuts, basic menus, etc. It works very similarly with how it launches built-in helper applications, handles network and internet integration, general window handling and options, and such. There are also themes that do a passable job of making it mimic Macs if someone prefers that.
I was/am a long-time Windows user who has been using Linux on and off since the late 90s and pretty much 100% for a few years now and it's been helpful for muscle memory and such. The couple times I've actually been in a position to introduce long-time Windows users to Linux they've preferred KDE. I'd always go for a KDE distro (even if Kubuntu, which I use a lot myself, since it combines the wide support of Ubuntu with KDE, although Neon is pretty interesting too) when suggesting something to a noob. I do like Manjaro but I might still lean towards Kubuntu or Neon just because there's so much documentation for the *buntus out there vs. Arch-based stuff, but either would be a good choice.