I don't really get the point of masks on a plane when you are sitting super close to strangers and then people also take the masks off to eat or drink. The thing is, unless it's a proper medical mask, it will not block 100% of the air - and so if you're sitting super close to a stranger who has COVID the mask may not provide enough protection. And since they are taking it off for part of the flight...

Some planes have modern HEPA filters that do such a good job that masks are superfluous. Others are not so safe... and for those, they should actually maintain social distance.

In other words - if the filters are old enough that masks are needed, then they should only seat every other row and only allow people traveling together to sit in the same row. And masks need to be kept on for the whole flight.

Vaccination status makes no difference if the point is to avoid spreading COVID, since vaccinated people can also get it and are more likely to be asymptomatic. Asking people to be tested within 24 hours before flying makes more sense. If you test positive - you can't fly.