The general rule is that as your opponents get tighter, you have to get tighter as well. This becomes cyclical. As you get tighter, they get tighter, as they get tighter you get tighter, until everyones nutcamping nits only playing AA/KK.

At some point in that cycle, once youre able to easily define your opponents hand, it becomes very profitable to play weaker cards against them, namely hands like suited connectors (NOT KQo) because you're going to either flop hard and suck out on villains obvious AA, or youre going to fold the flop and they're not going to make much.

I believe this is mentioned somewhere in NLT&P.