The thing is that there's no benefit to algorithmic social media, so erring on the side of caution is responsible. And we see a clear and extremely reasonable threat. The ideal benefit is that teens won't form a social media addiction.
Algorithmic social media uses the exact same principles as gambling addictions. Teens are much more subject to these exploitations and we don't let them sit in casinos all day and loot boxes have seen some regulation as well.
Social media may be even worse because the gamble is far less tangible, it's cost in the surface is only time and the reward is purely an emotional one.
I would support efforts at restraining exploitative use of algorithmic content for all ages. The main issue is that age-restricting teens especially is logically difficult and can create unintended consequences. Teens are going to act on their own and since many of today's adults (particularly of the generation that tends to legislate in the US) were not raised in a digital world, there will be groups of teens that are better with technology/computers than the adults making laws and therefore the laws either need to account for that (and requires controls so draconian that companies are likely to just ban the kids or stop operating, which opens up the 'what about lying' issue).
You mention casinos. One difference between casinos/alcohol/cigarettes is that there are easy places to intervene/place responsibility: the point of service is a physical location subject to local law. Digital regulation is a lot murkier and easier to exploit. (And not just by creepy adults: a lot of us kids in the 90s/early 00s picked up on the argument that if we weren't legally able to be held accountable, then we couldn't be legally held accountable for things like piracy either).
The only way to ensure something like this could be enforced would be to require ID for signing up for/into any algorithmic service and HELL no. Not only should we not throw the baby out with the bathwater, we also shouldn't set the cradle on fire.
Algorithmic social media uses the exact same principles as gambling addictions. Teens are much more subject to these exploitations and we don't let them sit in casinos all day and loot boxes have seen some regulation as well.
Social media may be even worse because the gamble is far less tangible, it's cost in the surface is only time and the reward is purely an emotional one.