The actual level of non-compliance was lower than predicted during the spring. It's gone up a lot, at least here in the UK. Unfortunately, our entire mainstream media pushed the idea that lockdown fatigue is a lie during the spring for essentially partisan political reasons and can't really back down now.
2. Flattening the curve is a strategy to lessen stress on healthcare by lengthening the time that the system can cope with stuff. A steeper curve leads to more deaths but ends quicker.
Thus. Lockdowns and people abiding with the rules does not make it end earlier, we want it to go on as that means a flatter curve.
To say the equivalent of "if you only wore masks this would have ended sooner and we wouldn't need lockdowns" is false but it makes sense at an emotional and behavioural level as most medicines, interventions, treatment promise quick results from compliance. It also more natural to blame people instead of an invisible virus for the crisis.
We want compliance so that it goes on for longer as that means less deaths.