There might have been some reason for masks early in the pandemic but at this point there is no valid scientific or medical reason for most people to be wearing masks. It's pure politics and virtue signaling with no significant public health benefit.
Flu and covid are spread similarly. The masks slow down the transmission of covid and flu, so you don't die. The indication that flu transmission has virtually stopped is an indicator that the transmission rate of covid could be much higher than it is.
https://peterattiamd.com/covid-part2/