I really depends on the masks. The cloth masks with a couple of layers aren't very effective because Covid is airborne in the sense the particles of liquid it persists in are typically 1-5nm in size and hang on the air and it survives for hours like that depending on the conditions. We know that N95/99/FFp2/3 standards block this very well and a number of studies done in places like a hospital in Cambridge showed they were extremely effective, maybe 100% effective at avoiding infections. The challenge is with these masks is they require a bit of knowledge on fitting and testing they fit correctly. Just drop shipping them into a random village didn't work and people have a tendency to do dumb things like breaking the seal to scratch their nose or taking it down to talk.
But when worn and used correctly they are extremely effective, the physics and engineering on which they are based has never been in doubt.
Cloth masks are not very effective against spreading of covid19, but they are effective against spreading of swine flu. Covid19 and swine flu both hit hard immune system for first time, so mortality rate jumps from 1.1% + 0.1% to 5.4%, or about 5x.
Not arguing but would appreciate sources regarding N95 masks. When I reviewed the literature in 2020, there was no solid evidence that their use led to improved outcomes, even in clinical settings.
But when worn and used correctly they are extremely effective, the physics and engineering on which they are based has never been in doubt.