A paid youtube? Not sure they would be worth it without the endless amounts of free content by free users.
Facebook? There are plenty of sites like facebook without users. Charge for an account.. reduce the userbase, the platform loses value without the free users.
A paid Facebook means it would be designed to actually serve you (instead of wasting your time) and people would use it to connect with friends instead of liking endless shitposts.
All your friends or anyone you want to contact would need to be paying customer.
If it is just friends why waste money on facebook just to talk. Most would rather spend that money on a more focused community/hobby like gaming and connect ingame.