Well, look, here is my use case. I have some really old hardware that I used to play with earlier in life, it’s located at the parents’ place. I still use that hardware, but not too often, since I live on my own. I could replace all that, as it consumes a lot of power indeed (comparing to SBCs). But in absolute numbers, they’re just regular computers, so power draw is somewhere at 60–90 Watt/hr, I suppose. Which is not that much, especially given I run the machines half a day once a month. What I learned over the years, you can utilise some servers by not running them 24/7. One server there, I wake it over LAN nightly, copy some backups there, and turn it off again. Very useful. So, I think I’d keep them running for as long as they’re alive.