I don't know why you are downvoted. There is growing evidence that the virus mostly spreads as aerosol and that the amount of particles you inhale dictates how sick you get. The so called super spread events account for over 80% of the transmission.

Bad ventilation and dry air keeps the airosols floating around making it easier for people to inhale them. The spread in meat factories is one example.

But a mask still can prevent a lot of airosols. While also being limited. There was research that shows a lot of air escapes above and below the mask if someone coughs or sneezes.