// If facemasks did the job that people say they do, the positive results wouldn't be increasing would they? //
If there are multiple factors involved, then why would this be necessarily an expectation?
The misconception here is clearly that an approach can only be "effective" if it strictly turns the rate of infection increase negative. This is a mistake, for several reasons. The most obvious is that, even if viewed in strict terms (R less than 1 = good, R greater than 1 = bad), one measure alone is rarely enough, but in combination they can be effective. Moreover, the combination is not necessarily linear. More, still, the target may ideally be R below 1, but if this isn't reached then keeping R as low as possible is still preferable. Mask-wearing has been shown to reduce R if it is widespread and encouraged practice.
https://www.pnas.org/content/pnas/118/4/e2014564118.full.pdf