Thinking this through....if two countries have equal risk (ie...

Thinking this through....if two countries have equal risk (ie both green zones), I wonder what the point of rapid testing and quarantining is for vaccinated people. I get it still reduces the overall transmission at least a little. But it seems a big imposition on the vaccinated when the risk of transmission and serious illness is significantly reduced. Then once people work this out for themselves, we will have a compliance issue. I wonder if we will eventually transition to only the unvaccinated having to rapid test, isolate or quarantine? This makes more sense to me.