I do like the dedication to Mint! To be honest it's generally my default pick if I need to slap Linux onto something. I actually tried putting it on the gaming table machine but for reasons I didn't feel like digging into it just did not cooperate, and Debian did.
CachyOS on the luggable gaming machine is mostly just because I hadn't used it before and wanted to give it a spin. So far so good.
As for the Windows machine, it's a gaming rig and at the time it was built, pre-steam deck, Linux wasn't quite yet in as good a position for that as it is now. I just can't be bothered to switch it mid-stream as it were. It's almost certainly going to be the last Windows machine I ever own though.
Old hardware is certainly possible. I salvaged it from my parents who were going to throw it out. It's got an A10-8700P and is limping along with a single 4GB DIMM. The thing doesn't even have a second memory slot.