I usually recommend Xubuntu (and probably 20.04) - because XFCE is fairly light still has a few snazzy bells and whistles and eyecandy, and it’s just as tweakable as Gnome or KDE - plus also if you do Xubuntu (VS e.g. Debian 10 with XFCE) - you get a much more recent version of XFCE (4.14 in Xubuntu 20.04, but only 4.12 in Debian 10 [might look like a minor revision - but there’s quite a difference between the two in my experience]).
I think there are other XFCE distros too… e.g. Manjaro? And isn’t there an XFCE built for Mint?
I run XFCE on my Pi4 machines, but 'cause I choose to run Raspbian (still using 32 bit version - waiting till the foundation has full hardware acceleration in arm64 buitl) for the later kernel version - I’m then stuck with XFCE 4.12 … XFCE 4.14 is much nicer…