From my experience of having to wear them on a daily basis over the last couple of months, psychologically it acts as a reminder and makes people more cautious in general.
The only place where i've been people 'taking liberties' is in a crowded bar where literally no one whatsoever was wearing...
Didn’t the WHO change it’s advice on them?
WHO urges mask use in confined public areas, where coronavirus still spreads
It’s not just that either, psychologically it makes people more aware and cautious and a reminder that things are not normal and to maintain distancing.