Facebook is a massive part of social media. Billions of users. It is apart of society in its sheer size. A society decided “we want to make this better” and acted appropriately. I think it’s a noble pursuit for a society to attempt to reduce the clearly negative aspects of social media.
There is no real freedom of choice. The network effect cements big players positions. Try telling an 80 year old grandma with a 20 year old laptop to use mastodon. Likely no one she knows is on it.
Finally, individuals make essentially no difference when choosing to not use FB. But when choosing to not go to a local bar, that may be 0.03% loss of their monthly revenue. The only actor that can reasonably bargain with huge organizations is other huge organizations.