That's complicated & as sword of spirit said in the OP of this very thread, there are a lot of things that make it tricky to answer; however there have been numerous "maybe something like..." & "I think that,.." suggestions that the people making the suggestions might help.... Unfortunately all of them resulted in the sort of acrimonious bad faith discussions I noted a couple posts ago. Some of those suggestions were things like more ritual spells & greater ritual spells. Bizarrely even suggestions like "cantrip versatility should be OnRest like spell versatility for the same reasons crawford gave for why spell versatility was being added to allow OnRest spell swap for sorcerers" also got shouted down with the kind of absurd ~"gitgud learn2code wizards are too strong" nerfherding so prevalent in this debate. Someone else has been bringing up the idea of letting wizards effectively buy a scroll & scribe it temporarily during a long rest for twice the cost of scribing it as some kind of carrot for putting a not very meaningful exhaustion mechanic on spell versatility; but aside from pointing out why the earlier versions were a meaningless restriction that amounted to "you shouldn't do this if you somehow have 4 points of exhaustion" the more recent versions don't really understand the wizard & are trying to balance an ephemeral somewhat trivial "I should wait to use this till I'm feeling lucky or can take a couple rests back to back" against a real and tangible "I can light this pile of money on fire to temporarily prepare a spell I may or may not be able to spend more money to scribe to my spellbook when I'm already a massive money black hole of the party". It's unsurprising that the inability to discuss these things without people coming out with specious argument based on cherry picked data, willful blindness of rebuttals presented, & so on did not create an environment where people were interested in going back to square one & starting the whole cycle over.
Except spell versatility was stated to address the issue where spells known casters weren't able to change spells as often as originally intended after years of observation. That's what it does and spells were always meant to be changed with these classes.
Cantrip versatility isn't meant to balance out some buff people think spells known casters just got. It was to allow for respeccing without needing DM fiat. That's what it does.
Everything else is white noise arguing regardless how it's justified. Those are simple goals with simple solutions.