I've been thinking of making my 2012 a linux machine at some point - it's low on my priority list right now though. You run it with no GUI at all?Interesting, hadn't thought of that. But it runs just fine under parallels on my 2018. Meanwhile, the 2012 is now a linux-only machine, MacOS is no longer installed at all (but I have a bootable clone on an external SSD).
With Intel Macs going over the hill slowly the focus will soon land on the M1 Macs and what becomes of them and other Apple Silicon machines. Makes you wonder what happens when Apple inevitably make them obsolete if you need up to date OS. It's another reason not to overspec machines I guess.