I think there really is an issue with social media - indeed with the web itself. Partly because children are growing up with a fast changing media environment that their parents are also learning. The challenge isn't met with bans - the primary duty rests with parents - but with harm reduction strategies. Also, in the same way we socialised kids going to bed at seven or eight pm, we need to develop social tools - supported by good safety advice - that allow parents to control their children's use of the web.
What's clear is that growing up in the years since the mid 2000s has been a bit of a wild west. Parents didn't appreciate how troubling some of the content out there had become - the job now is to give parents the tools and information necessary to allow them some degree of peace of mind. I'm not sure simple bans and curfews - each requiring adults to ID themselves before using sites - are the solution. Not just because de facto forcing adults into a digital ID is wrong but because this doesn't mean children can't and won't breach the walls you build.
Finally smoking kills something like 70,000 people in Britain every year. There are a handful of tragic cases related to social media and some contested evidence about harm to mental health (although lockdown did vastly more damage to children's mental health than social media can even imagine). Calling social media "as bad as smoking" is simply another moral panic, a piece of ghastly nannying fussbucketry designed to scare people rather than help people. Anyone making this claim is a reprehensible shyster.