What Why can't I find a USB-C hub with multiple USB-C ports? was looking for did not exist at all previously (except for one Dell hub). Yet, people posted many answers because USB C is confusing or they just wanted to be helpful and of course they totally failed because they answered a totally different question. Moderation also failed because these answers were not removed but I digress.
This is now all moot. One of the things the new Thunderbolt 4 hubs are capable of is when connected to a host which only has a USB C port with DisplayPort alternate mode capability, no Thunderbolt at all, is passing on the DP alt mode signal to downstream. Which is exactly what the question is looking for. This capability makes all answers, which boils down to "no such things but here's something else" anyways, completely obsolete. The answer is now: get a TB4 hub.
Since it's so chaotic I have not posted this there yet because I do not know how, do I edit the existing TB4 answer which does not have this backwards compatibility information? Do I post yet another answer?
I tried to edit the top answer https://superuser.com/posts/1414046/revisions and it was rolled back. Very frustrating!