Well that’s good, but obviously things are different now. Kids are back in school. People are dining out, and having larger indoor gatherings etc... people are behaving differently.
And yes, recent political rallies and celebrations are certainly contributory to the recent spikes.
Lots of studies out there that show masks, even cloth masks, reduce the amount of virus you spread and the velocity of the output. Masks didn’t become less effective over time. They are not 100% effective, Or even close to it really, but they are an improvement and will increase the amount of time you can be near someone who is infected before you take in an infectious dose.