> It sucks as a parent because you get this from both ends: “parent better! (Putting in tons of work that our parents didn’t have to)” and also “lol what are you doing restricting kids on computers is impossible, give up you idiot”.

I didn't claim that it's impossible, merely that it's difficult sometimes, as you also implied ("putting in tons of work"). The advantage of physically consfiscating phones is that it's a low tech, brute force method available even to the least technically sophisticated parents.