I am a pescetarian, so I don’t have too many complaints about eating seafood. It is certainly better for the environment, although the fuel involved in catching the fish and then overfishing are arguments against eating seafood.

Insects I’m not sure about, I don’t think they are eaten at the same magnitude as beef or lamb, so the issue isn’t as severe.

From a personal perspective, becoming a pescetarian is certainly a viable alternative. It works for me, If I want to have days when I only eat veggies then I do. While I can have days where I eat seafood again.

Honestly, I think this will all be immaterial when lab-grown meat becomes more mainstream. You will be able to something that looks like beef, tastes like beef, but has none of the bad side-effects of beef and doesn’t involve the intensive farming processes currently used.

This will be the viable alternative as it will become looked down upon to eat meat when you can eat basically the same product which involved no slaughtering or terrible farming practices.