People do mistakes with masks (often intentional), forget to wash hand after firmly holding door handle that was touched by 1000 other hands on that day. People have small kids which is a vector you have practically no control over. People do family visits where all masks go off. Folks go to restaurants and as soon as they have drinks everybody acts like covid disappeared suddenly.
I firmly believe average human is simply not mentally equipped to keep constant vigilance and cover all potential routes. It tires everybody rather quickly.
As for N95 masks, neighboring Slovakia has them mandated for quite some time too and it didn't prevent them being 2nd worst globally in new cases few months back. Why? Well 50% of population not vaccinated is a good start. Opposition politicians in good old Trump manner attacking any covid measure government puts in or science in general, generating a large pool of antivaxxers over time. Bravo, that's one sure way to get a lot of blood on your hands without ever pulling a trigger.
I really see omicron as kind of godsend within limits of current situation - I would cancel all measures and open everything, brace for a month and let it run through populations. This prolonged agony and ineffective lockdowns that prolong general agony ad infinitum wreak havoc on kids and tons of professions, and frankly on almost everybody in some way.