Children will always network, and share ideas and form community. They don't need to do it on a platform designed to exploit as much of their attention as possible as a way to sell advertisements.
I think children should be able to congregate safely online. If you think a meta-owned platform is a good place to do that, I've got bad news for you.
I think a lot of my generation owes a lot to the internet during our formative years too, but the idea that Meta offers anything other than a curated stream of addictive ragebait nowadays is for the birds. Maybe this ban will encourage teenagers to hang out in less corporately owned spaces online. I can hope.
An outright ban probably won't work, but it sends a signal that perhaps society needs to use the internet better to be a benefit.