Agree: Processing power on the macs are not an issue and is not a technoiogy challenge and more of a solution availability problem. The signal transmission really is getting to the edge of what is available at the moment. 6K/60Hz is already at the limit of TB4 bandwidth. 8K/60Hz and beyond really needs TB5/HDMI2.2 if using a single cable.In other words, no.
I'm not quite sure why you think this is relevant in a thread about 8K UHD monitors. 8K UHD 60Hz has been supported since M2+ Pro/Max/Ultra and M4+. Pro Display XDR runs on 2019 Thunderbolt 3 Apple hardware, not to mention all M1+.
The benefit of high DPI depends a lot on the application and the working distance from the display and there is unquestionable benefit for a lot of use cases.