Brit here. I'm ambivalent about it. We'll have to see how it works in practice. I don't think the idea is that it's impossible to access harmful content, just that it's trickier so kids see less porn, self harm advice and so on.

So far the only thing I've noticed was Reddit asking how old I am. We've had a 'ban' on piracy sites for years which remains trivially circumvented.

We also ban online paedophile networks but I think all countries do that? That one you go to jail for.