I don't understand how a 10GbE adapter is possible without Thunderbolt, or why not being Thunderbolt makes it smaller. In my experience USB speeds faster than 3 don't happen in practice unless you have a Thunderbolt port and device. Maybe I just don't have devices that use the faster USB speeds, but Thunderbolt has always been the one and only way to exceed the speed of USB for me.

I think USB 4 exists based on the Thunderbolt spec (or the other way around?), but doesn't require any Thunderbolt capabilities and therefore isn't very telling.

I think Apple's approach of supporting Thunderbolt 4/5 on every USB port of the MacBook Pro is the only sustainable way forward.