you can absolutely run e.g. datacenter-level A100 at home, there are adapters from the SXM to the PCIe socket. Haven't seen people running SXM versions of H100s this way but this could be due to the price factor only

Well technically true, I would wager that the home lab is going to require increasingly distinct and unusual adaptations to retrofit the hardware to home use.

New stuff is all liquid cooled by default and that's a paradigm shift for your average home lab.

I'm less aware of exactly what's happening on the power side of things but I think some of the architectures are now moving to relatively high voltage DC throughout and then down converting it to low voltage right before it's used. So not exactly just plug-and-play with your average nema15 outlet.