The biggest push may indeed come from the Steam Deck. A PC in a handheld form factor, that allows you to hook it up to a monitor for a full KDE Plasma desktop experience. Very exciting. If we see a lot of people enjoy it and the Steam Deck is a success, you can be almost guaranteed that more devices will come along and slap SteamOS 3 on it and then also have a KDE Plasma desktop available.
I can’t seem to find anything on verified boot from Windows or macOS. There’s secure boot, but that’s something a lot of Linux distros also have.
Regarding permissions in Apple systems, yeah they are better than Windows and Linux, but they are still way below the level Android provides, which seemed to be the root comment OP’s intent.