Jurisdictions are already lining up to slide down the slope as fast as they can. New York intends to mandate real verification and anti-circumvention measures at the OS level. There is no room for compromise: any jurisdiction attempting to compel what must be included in an OS is batshit insane and normalizing this is going to very quickly lead to JesusTracker.exe being mandated by Texas and CrocCam.exe by Florida.

Contrary to your belief that if we just give them an inch they won't take the full mile, I think it is very important to get people rallied against OS modification altogether. If you take a murky position like "a little bit of age verification, as a treat", and sell people on voting for that / not protesting it, all you're doing is priming the average person for accepting age verification no matter how invasive. Average Joe isn't going to understand the nuances of when age verification may or may not be tolerable, nor is Average Joe going to understand the nuances of when compelled software inclusion may or may not be tolerable. If we want to get millions aligned in the same interest, the message needs to be extremely clear and straightforward, communicating exactly how bad of an idea it is to let each and every jurisdiction compel their own form of surveillance into your OS.