[avidiax]

Mandates of any kind tend to have inertia: once the mandate is in place, the government/corporate apparatus is in place (and usually generating cash flows), it's often a similar amount of effort to get it removed and restore the status quo. That's part of the "slipperiness" of the slope.

The other part that may or may not be the case, is a tendency to expand the scope of a mandate. This is in part because the companies that derive cash flows will always want to increase them. It's also because the existence of the apparatus is attractive; it's an existing solution that can be coopted to new or expanded ends more easily than coming up with a new solution. And the ease is not just in implementation; it's also that the precedent is set so the opposition may be less powerful.

In this case, I think the recent trend in school board elections and local library funding of banning minors (or everyone) from materials on sex education, sex positivity, LGBTQ stories or discourse, etc. suggests how any age verification program might find public pressure to increase in scope.

Where it gets more dubious is the possibility of expanding the scope beyond minors (to identifying or simply banning everyone) or beyond materials of some (potentially alternative) sexual nature, i.e. to political, religious, foreign or technical subjects.