Why not? The church choir got it without masks (large room, with spacing). The salon was mostly masked and it did not spread. So masks can limit the spread.
Reasons not to wear a mask: interferes with breathing. Slowing down the spread doesn't change the inevitable outcome. Personal carefulness: you choose not to talk in public, only breathe your nose and don't go out if you are feeling ill. The principle that it is illegal to quarantine or restrict someone who is not ill. Other reasons?
“The church choir got it without masks (large room, with spacing).”
The church choir got it early on. I’d bet money - if one can in church - that someone in the choir was coughing as well as singing. Based on my time in various church choirs....