MX Linux would be another option for a desktop-oriented Deb-based distro.
But the packages aren't really newer than Debian (some are, some aren't).
Honestly, I'd just run Debian, get kernel, drivers and firmware from Backports if necessary and install Flatpaks for software I need to be newer.
I don't need the latest, freshest version of the KDE printer setup utility to be honest.
But in general, it's always better to fix your issues on the distro you have. Mint is what you're looking for. KDE does support Wayland, all it needs is in the repos, and there would be no point for Mint to patch that support out.
Do you not have a "Plasma (Wayland)" option on the login screen where you choose your session?