Based on…? I’ve been on 4 Delta flights in the last 3 months and the flight attendants were militant about masks. They told a woman in front of me on one flight that if they had to tell her to keep it above her nose a third time she was going to be banned from future delta flights.

From personal experience, KLM is quite lax about it.

Regardless of airlines, masks come off for drinks and snacks. They remain off as long as you look like you're still sipping on that coffee and when you're done, they're usually only loosely enforced back on. It really is a big joke.

You tried Delta flights but you didn't try Omicron flights :-)

its never too early for humour