I think what he means is that government derives its authority from people respecting its authority and following its laws. If everyone in the US woke up tomorrow and agreed that we were better off if we just abolished the government, it would cease to exist. The fact that that hasn't happened suggests that people on some level feel that we're better off if we don't do that. I don’t think this is a very strong argument though; e.g. in a place like North Korea, it’s very difficult to overthrow the government even if a lot of people might feel that would make them better off.

I agree that people don’t “consent” to being governed just by virtue of being born, but I don’t think it’s possible to have a world where people consent to being a part of every power structure they’re forced to participate in, nor to have a world without such power structures.