Many memes posted on social media question the effectiveness of face masks by asking why measures like lockdowns and physical distancing would still be necessary “if masks work.”
These memes oversimplify the concepts of risk and protection by portraying them as binary concepts that either exist or do not exist. The reality is that risk and protection exist on a continuum. Scientific evidence has demonstrated that face masks reduce the transmission of viral respiratory infections like COVID-19 to some degree. Practicing physical distancing and proper hand hygiene, along with wearing masks further enhances the effectiveness of face masks.
This is analogous to measures used to improve traffic safety, like seatbelts, which significantly reduce the risk of injury or death from a traffic accident. But seatbelts alone do not remove the risk entirely, hence they do not render additional safety features such as airbags and brakes redundant. In spite of this, one would not argue that seatbelts are useless simply because they do not prevent all risks.