100% mask mandate didn't stop it from running rampant through my workplace last and this year (global corporation). It didn't stop me from catching it despite complete compliance with the mask mandate and all the other security theater/cleaning protocols/etc. None of those also kept me from having it and not knowing it due to no symptoms until it was too late to not go to work while contagious.

I seriously wonder how many asymptomatic cases there were/are because I had no idea until I realized I had zero sense of smell other than I thought I had a head cold. My job told us "if you felt sick use standard call in procedures". We only have 4 sick days per calendar year and COVID was NOT an exception to that. If you took off and did not test positive, the entire time off counted against you plus you aren't paid so you only get 1 chance to be wrong.