If anything, the overwhelming majority of Apple enthusiasts have gone all-in on Apple Silicon. I sincerely doubt those using old Macs as servers are anything but a rounding error.
Maybe among the general mac population they are a rounding error. But among the mac population who actually peeks behind the curtain and uses homebrew?
If your clients are all macs it is just nicer keeping the server on macos imo. mac os is unix after all so you don't have any software incompatibilities for tools you'd probably run on the server. Time machine support on the server is built in, instead of being a sort of hack with samba if you wanted to try and run it on a linux server. I haven't messed with it much but there might be some clever stuff you could do with applescript and triggered actions, maybe schedule your compute jobs from your calendar app for example.
I held onto a 2010 Mac mini server for like 11 years before retiring it due to hardware problems (blame the hot room). Time Machine is the only thing I can think of that was still relevant at the end, and even that you can do with any NAS supposedly. The macOS Server stuff was way eol, and anything worth keeping had better Linux equivalents.
Yes, to such a stunning degree that I’m having a hard time believing you’re serious. The M1 was utterly transformative. The install base of homebrew is enormous. The proportion who are keeping old Mac hardware around as home servers is minuscule. The proportion of those who are keeping old Intel Macs are a fraction of that, and the ones who aren’t just running Linux on them are yet another fraction.
That’s not to say you’re crazy or anything. You do you. But do understand that you almost certainly constitute a nearly irrelevant minority of users of homebrew.
Intel homebrew is larger than Linuxbrew, yet I think it'd be shocking if they dropped support for Linuxbrew.
Old machines still work. They're still deeply useful. I'm still using daily an Intel Macbook with homebrew on it. When I no longer use it daily in some years more, it'll still make a perfect server.
