It doesnt make it easier for them down the road, if anything it makes it harder as there’s the ability to say “but we already have that”.

This is perfectly reasonable, but my feeling is that the real world isn't reasonable in this way.

Consider all the infractions of liberty that have been approved in the name of combating "terrorism." The no-fly lists. The universal warrant-less searches. All domestic communications recorded and archived for who-knows how long. The pervasive surveillance. The huge extension of CBP power to do things like raid Greyhound busses that aren't even crossing borders.

None of these steps were prevented with the argument "But we're already doing something about that issue." That argument never even came up, to any noteworthy degree, in the public discourse.

Look at it this way: All sorts of websites that aren't for kids already have banners requiring the visitor to affirm that they're legal adults. So, we're there: "We already have that." But no one is seriously making that argument. Because, of course, those banners do next to nothing: Visitors can just lie. So it will probably be for OS level age verification. Thus, in creating a system that doesn't work, the excuse for extending the system, to exert more control in the future, is built in from the start.

People who are interested in asserting more control over others are never content with the amount of control they have. They always want more. It is the gaining of more control that motivates them.