What evidence is there that masks prevent lockdowns? We've been wearing masks for months now and lockdowns are coming back regardless.
Only half of us have been wearing masks. For places in which rules were stricter and compliance was wider-spread, see countries that currently don't have lockdowns.
As a counterpoint, in Spain where I live, mask wearing in public is very high (Statista says 95% always wear a mask) and we still have a lot of lockdown measures, as infection numbers are still fairly high. You could argue that we have lockdown in spite of high mask use, due to cultural habits/private meetings/bad laws/low compliance of other measures, but it shows that high mask use alone isn't sufficient to avoid lockdown.
This simple messaging from a credible leader would suffice. What didn't work is the idea that masks prevent something we can't control. The hard problem is solving for credibility.