If you are in a closed environment with many people exhaling then even an n95 mask will eventually let some virus into your nose. The viral load or inoculum should be much lower than otherwise, though, if everyone is wearing masks since the masks inhibit the amount of aerosol spewing into the generally shared air supply. A lower load for most people means a less severe infection. Valved masks allow more aerosol to escape, thus they are generally frowned upon.
Masks have always been mostly about protecting everyone else from the wearer of the mask. That is why people who argue that masks restrict their freedom have a weak argument. It is one thing to complain about being forced to avoid risk, but another altogether to insist on the freedom to put others at increased risk.