I agree, I think kids should have limited access to the internet. I pretty much did and it worked out for me but I have seen so many reports about it causing harm in schools and personal life. (Specifically I think LLMs should not be used in education also, but different point) However, I think the main problem people have with this "think of the children" narrative is that it will force EVERYONE to give up their credentials to access the internet, not just kids. And the general consensus is that we as adults do not want to and should not have to prove our identity to access the internet.
I am wholeheartedly against identity verification, especially when it comes to giving up privacy. And I hope these "think of the children" arguments can be pushed back at from multiple angles. If the danger is real, then by the time a child is online, 4 out of 5 in them in Australia can apparently access social media anyway. So even if everyone's privacy was somehow an acceptable price to pay, these requirements do nothing.