The point on people being happy with slower CPU cores is kind of weird to bring up with a server. Most games don't push CPUs that hard, you usually need a really expensive GPU before you see noticeable benefits in gaming from faster processors.
Having done some core critical work for the last few years (media processing/systems programming), my recent upgrade from a 4th gen i7 to a Zen2 CPU is paying in spades. If I was building a server to do some of the batch processing stuff I'd like, I would definitely invest in a faster, cooler, more power efficient machine. But that's just me. I don't think I could beat that price point though.
It sits powered-off most of the time though because I haven't been able to put it to good use, yet.
For a while it was running my Unifi controller + Pihole ... but you don't need the Unifi controller unless you are actively performing maintenance, and Pihole happily hums along on a Rpi 3 that uses far less power.