I hope it was wrong, but it seems at least plausible to me. I'm sure that probably fixes could be made for all these issues, but the reason the current paradigm works is that, other than the motherboard and CPU, everything else you need is standard, consumer grade equipment which is therefore cheap. If you need to start buying custom (new) power supplies etc. to go along, then the price may not make as much sense anymore.
The troublesome hardware is the stuff with custom backplanes and multiple daughterboards each hosting a node. Also AMD CPUs that lock themselves to a single motherboard.
I personally feel like I will downscale my homelab hardware to reduce its power draw. My HW is rather old (and leagues below yours), more recent HW tends to be more efficient, but I have no idea how well these high end server boards can lower their idle power consumption?
When I was looking in October, I hadn't bought hardware for the better part of a decade, and I saw all these older posts on forums for DDR4 at $1/GB, but the lowest I could find was at least $2/GB used. These days? HAH!
If I had a decent sales channel I might be speculating on DDR4/DDR5 RAM and holding it because I expect prices to climb even higher in the coming months.