I tested it a bit in a VM to get familiar with pacman and yay. Latest KDE Plasma 6 and more snaps in Ubuntu's future are the main reasons I want to switch.
As I don't use a separate home partition, I have an extra drive with BackInTime home dir backups and virtnbdbackup snapshots.
Is EndeavourOS stable enough for everyday use and would restoring home with BackInTime just work (as root user)?
Just an update, I successfully switched my whole user data to EndeavourOS and installed almost everything I have used before. Works nice and smooth with KDE Plasma 6 in Wayland (although an NVIDIA downgrade to 535 is required for gaming until the latest driver is fixed).
(I disabled the Polonium tiling for the screenshot.)
Edit: Switched to Arch today :)