On my recent Moon cruise masks were only required in Venetian Lounge and on busses. Enforcement was hit or miss but when I asked staff to remind pax they complied. A minority of pax wore them as often as possible such as in the hallways, at buffets, elevators, while not actively eating, gym, etc.
Canderson, nothing is 100% so whether a mask is “properly” fitted or not it will help to mitigate. That’s the best the general population can do along with vaccines and boosters.