This applies not just to social media, but drugs, alcohol, porn, etc. Yes, laws and IDs add friction and that's good, but if a kid really wants those things they are going to find a way.
Social media already had built in friction without needing new regulations and ID requirements. To access social media you need a relatively expensive (for kids) device and some way to connect that device to the Internet, which is also not free.
The biggest problem I see is that unlike alcohol, drugs, and porn, there are seemingly benign reasons for kids to use social media. Sports teams, dance classes, youth groups, etc. all want to keep in touch and allow group communication. Too often the adults in charge turn to Instagram or whatever social media app for the group communication. Now, unfortunately, your kid needs an IG account.