The evidence is pretty mixed, and even the studies showing the strongest effects have mask wearing yielding something like a 50% reduction in transmission.
I haven't seen anyone model what this looks like on longer timescales. Does this mean that you're just delaying the inevitable? If so, and the disease is mild and we're not going to overwhelm hospitals with the infected, what's the benefit?
You can't do a study that way. People do or do not wear masks based on emergent social acceptance, regardless of government actions. If you want to do a discontinuity study you have to evaluate actual mask usage in the real world and discover a boundary discontinuity. You can't just do it by jurisdiction and assume that the government proclamations work. People wear masks when they aren't required, and they may not wear them when they are required.
Yet we’ve been hearing since the beginning of 2021 that they’ve been proven to have been much more efficient by the coalition parliament which has come up with this idea.
It's trivially easy to acquire authentic N95s today.
People just won't wear them, so, we all suffer.