It’s not cool that content would be restricted to people that can prove they are older than 16. It requires very little imagination to see how this could be extended to restrict content to people that have a yellow star on their clothes.
This does not follow, in the same way that the existence of the police does not imply a slide towards a police state. The slippery slope fallacy is a fallacy.
Besides, at least around here they already ask for an ID if you look young enough, for some movies. This is not enabled by new technologies.