They lack some important things you need in a datacenter like hardware management platforms. You also can't upgrade components or add interfaces (which at their cost point makes some sense).

SBCs have generally been hobbyist oriented. It would be interesting to see some be datacenter oriented.

I think there is bias against them because they are so cheap. But they are arm64 and with 4 or 6 cores now. Still slow compared to an Intel/amd desktop but just always ssh/sshfs into them from your primary machine. I do this with vscode and it is great. Even better if you primary machine is Linux based.

The main problem that I find with current SBCs is their limited DRAM. Trying to compile stuff I can't keep all cores busy.