This would make it harder to make a social media account, make it harder for people to try out new platforms thereby cementing the monopoly of the current ones,

This would make it harder to make a social media account, make it harder for people to try out new platforms thereby cementing the monopoly of the current ones, make it impossible to make an account without giving your real name to the social media platform — something which people will also be especially reluctant to do with new platforms.