I actually have Wireguard running on a pi zero 2, all it really does is provide me my pihole DNS.
Edit:
I should say I have pihole running on a couple of pi 5’s currently, overkill yes but one of my pi 4’s was sacrificed to the whims of magic smoke another was donated to a friend and another now hosts HAOS, I have a few pi zero 2’s (only one was sacrificial) the one that hosts wireguard has one of my last few working SD cards. The pi 5’s host many other things other than just pihole.