I'm not really up to date on homelabbing hardware, but I'm surprised to see how much the whole thing is centered around raspis given how expensive they are for their relatively low capacities. Possibility of offgriding your homelab is an interesting project but not what I'd center this "revolution" around given most homelabs stay, well, home.

DIY 10" racks for second hand mini PCs would interest me way more but looking at the YouTuber's big lab racks affordability doesn't seem to be much of a factor.