"Common sense" < Studies demonstrating the relative effectiveness of cloth masks.
It isn't even "common sense". Air leaving your body through your nose and mouth at normal velocity will take the path of least resistance. With a mask on, it will escape out the sides and bottom but particularly around your nose and up. That is significant. The virus is carried in three ways- heavy droplets, light droplets, and aerosol. The heavy droplets fall to the ground pretty quickly. Unless you more or less face someone and sneeze into their face... most of those particles aren't going to make it to them. The aerosol and light droplets however linger in the air... and those are the particles that escape pretty easily around a mask or bandana. They can also go through many home made masks.
The Koreans and Japanese kind of had this pegged from previous viruses. The sick should wear masks and wear them correctly or preferably stay home. During significant outbreaks, you protect the most vulnerable and particularly the old.
Generally speaking, it isn't a great idea to spend a lot of time in someone else's "box" before, during, or after pandemics.
I've seen a couple of different peer reviewed studies saying that masks have limited value to prevent the spread of germs and can do harm. At least one and maybe both were conducted before Covid... meaning they weren't political. Just some boring report that only a few had any interest in.
