Yes, because that's how quarantine works. It's not about keeping you and your virus away from the world, it's about keeping you and your virus *potential* way from the world. Unless you've got some sort of realtime virus monitoring test strapped to your arm that I'm aware of, you have no idea if the uninfected person actually is an uninfected person. Symptoms don't show up in the first few days of your contagious phase, and some people remain asymptomatic.
The same way that "it can't hurt if only *I* go to the beach" showed itself to be spectacularly flawed in the UK when it turns out no-one has these ideas on their own. Similarly everyone buying an extra pack of bogroll and moaning that there weren't any left on the shelves due to everyone else's "panic buying" (but not them...)
Just f**king stay at home and stop being so f**king selfish. It's this behaviour that's necessitating the monitoring, because imbeciles think they know better.