It's as stupid as trying to legislate that kissing can't happen until 18. It's not practically enforceable and trying creates unintended consequences.
Not trying creates the unintended consequences of a double suicide rate.
Maybe it's worth trading one set of unintended consequences for another.
I've searched around and can't find the numbers that you're referencing. I can't even find a study that confidently asserts even correlation. It's just "the suicide rate went up in 2010's and we think it might be social media?" So to not only say that this is the problem but also this is the magnitude of it implies a level of confidence that is simply not supported by the data.
Kids who start using a phone when they are 6 have no curiosity for it. It's always been there, so what? On the contrary, they'll be the one who don't understand that what's put online for 5min is literally there forever.