I wonder if we can invent a new convention, of compacting last names. So, if John Richards and Mary Jones have a child, they can give it the last name… Jords. Or Richnes. It only really needs to go out for four or so generations anyway, at which point the folks who have a really strong attachment to the name will be dead. Plus the middle names provides a slot to put your family tree’s most famous name anyway.
I know some couples who have gone this route— both taking on a different name at marriage, either a combination of their names or a new one invented from whole cloth. It's definitely a workable option in terms of equalizing the "loss of identity" piece and ensuring that both parties are as all-in on the newly-created family unit.
That said, it does also feel a bit more chaotic and potentially subject to widespread adoption of surnames that are trendy in popular culture.
Depends on the jurisdiction, for example Germany is pretty strict.
If A marries B, then either both keep their names, both will be A or both will be B or one or both will be A-B or B-A. No other outcomes are possible, and if one of them was B-C before then the kids can't be A-B-C.
