While I don't condone the ad hominem name-calling, I do still have to agree with the point that if the mask does not provide much protection for inhalations (because it does not create an airtight seal or provide an actual barrier for the mouth, allowing air to enter around the edges), it provides minimal to no protection as far as exhalation go as well (because air can escape from around the edges and it's not an airtight seal). If a mask were to be worn so that it created an airtight seal, it would ostensibly have better results.
"Whereas the surgical mask provides moderate (>60%) and excellent (close to 100%) particle exclusion below and above 300 nm, respectively, the tests carried out with the 1% opening surprisingly resulted in significant drops in the mask efficiencies across the entire size range (60% drop in the >300 nm range). In this case, the two holes were ∼0.635 cm in diameter and the mask area was ∼59 cm2."
Excerpt from a study on mask efficiency, here, for your consideration. https://pubs.acs.org/doi/10.1021/acsnano.0c03252#
Obviously masks are a traditional anti-pandemic method used since the early days of man, but I think it's certainly imperfect, especially with the in-depth studies we're able to do in textile science. So, i think it would be fair to say that the mask does not STOP the spread of the virus because that seems to deal in absolutes. I would say the more accurate thing to say would be that the mask gives a slightly higher potential of not transmitting the virus, Because we're dealing in probabilities and potentials with the virus rather than any distinct black-and-white truths, unfortunately. I apologize for the length.