Reduced, no. The best available evidence is that it would have made no difference either way. Sad and depressing but that's where the data takes you. This is physically possible for any virus that can spread long distances on air currents including through air ducts, as SARS-CoV-2 can (just like its predecessor SARS-1). As it's not possible to be outside 24/7 nor to wear a mask inside 24/7 regardless of mask type, the chance of not being exposed fairly quickly is pretty low. The epidemiology of airborne respiratory viruses is not the same as measles.
The best evidence of this is still the nearly controlled experiment that happened on the Diamond Princess cruise ship early on, which was completely ignored afterwards due to what it showed.
I mean I honestly don’t know how there are people still repeating this lie that masks didn’t or don’t work.
Hundreds of thousands of people spent days in our hospitals. If PPE was not effective, every doctor and nurse in the country would have been sick by week 2.
Doctors and nurses did get sick. There were plenty of reports in the very early days about doctors dying of COVID, or mass absences of nursing staff. Then they got immunity and went back to work.
Masks had no effect. This isn't a lie. Look at any graph of cases from any country you care to pick, then try and draw a line where mask mandates were added or removed. You won't be able to, because even when a whole population was forced to start wearing a mask overnight there was no inflection in the graphs. The point of everyone wearing masks was to slow down the growth in those graphs, or even put it into reverse. Yet nothing happened. This is absolute proof that they did not work.
That's why the argument for masks always ends up relying on invalid lab studies using mannequins, or self-reinforcing models that just prove their own assumptions, or arguments of the form "people just didn't wear the right kind of masks". When you look at what was actually tried, the ground truth data doesn't show any effect.
The fact that you can't see where mask mandates went into effect isn't an indictment of masks — it's about the effectiveness of mandates. People were already wearing masks before the mandates, and people who were dead-set against masks continued not wearing them after the mandates were in effect.
Regarding doctors and nurses, they are trained in how to wear PPE and are much more likely to do so appropriately than civilians or (especially) children. PPE can be effective against COVID, but probably 1-5% of civilians wore masks according to protocols. Wearing a mask incorrectly might help, but AFAIK there are zero studies on this.
These findings indicate that countries with high levels of mask compliance did not perform better than those with low mask usage.
There are literally no correlations anywhere to be found. No impact on case numbers (the goal!) and no link between compliance and outcomes. That's because masks cannot stop an aerosolized gas from entering the body, it just goes through or around them. Aerosolized agents can also enter you via the eyeballs, which is why real gas masks also protect the eyes:
This sort of thing is why masks have no effect and at first health officials said that. They were right. But governments wanted to do something, and that was something, so public health "scientists" swiftly fell into line and overnight "the science" was suddenly saying the opposite.
The best evidence of this is still the nearly controlled experiment that happened on the Diamond Princess cruise ship early on, which was completely ignored afterwards due to what it showed.