As detailed in this post, RTL8153 with Mac also regularly hops down to 100 mbps and doesn't return back to 1 gbps: https://overengineer.dev/blog/2021/04/25/usb-c-hub-madness.h...

A pertinent question, however, is: how do you know what chips an adapter uses, before buying? I'm in utter dread regarding the prospect of buying a usb hub, since just like in the above post, they're black boxes to me which of course turn out to repackage the same Alibaba junk with 10x markup.