You don't get sick from a single virus.. you need a viral load that will overwhelm your immune system's primary defenses. So, exposure can still be sufficient limited by reducing time spent near other people. As long as nobody is coughing, singing, yelling, or laughing with their masks off, and their time spent posing is brief, there's very little chance of spreading a significant enough viral load.

Time in proximity, keeping distant, wearing masks, washing hands (and not touching your face) are all relevant factors.

This is why contact tracing is concerned about the people you spent significant time with, and not everyone you passed on the street to get to those places.