I started on Elitedesk 800 G1s when Raspberry Pis got hard to find and expensive, and I now feel they are better in every respect if you don’t need the GPIO pins.
Every time I open them up to upgrade something I’m impressed with the level of engineering. There are quality manufacturer manuals for them, the cooling is good and they look great
I started with three to allow for high availability clustering (under Proxmox), but really that’s probably excessive for my situation. So now my production stuff is all on one, and backups go to the NAS. If PVE-Prod1 failed, I just turn the second one on and pull the VM’s in from the NAS backups - takes a few minutes, and I actually run everything off it for a week every couple of months to ensure my recovery systems is all working.
The third one I use for software development and other testing of new services. I could have easily managed with two.