There's of course a whole legal system that has been dealing with this since for ever.
If I were to implement it myself, I'd use a third party service like those that can verify passports and driver's licenses and so on.
The friction free restoration flow is what Google is missing because they don't actually follow the DMCA process. Amend the law to strip safe harbor immunity in this scenario and suddenly we'd see abuse effectively combated.
We’re bending over backwards to accommodate a need to validate identities in a system (the internet) which in many ways started as an open/anonymous idea. I’m sceptical about most of all this. Google as a platform clearly have a responsibility for content, but are not allocating enough time/money to truely fix the problem. It’s like they have this MASSIVE problem at the very core of their product, and the only solution is spending tons of resources to truely moderate/investigate and proactively avoid incidents. But they should. SoMe/Big Tech are all cheating and their margins should be lower (and more sensible, compared to other industries..) if they had to follow common sense rules that forever applied to market places, news papers, public space - I mean, if you own a wall facing a crowded street, and someone paints a nazi symbol on your wall, then you have a problem.
Notaries do this all the time often for free or for a fairly minimal fee.
The solution doesn't have to be perfect to be better.
If counterclaims require doxxing yourself under penalty of perjury, then I would assume that's still perjury even if the other guy started it, so just making the counterclaim process easier doesn't fix the problem.