>...beef... the most environmentally impactful meat... Pork is less impactful and poultry is even less

This is largely because pork is raised in factory-farming conditions that are awful for the animals, and poultry even more so. Environmental "benefits" are countered by animal welfare drawbacks.

Here is a good analysis, you need to scroll around a bit to find pork and poultry info:

https://slatestarcodex.com/2019/12/11/acc-is-eating-meat-a-n...

I think impact is largely based on lifespan required to rear the animals.

Beef is more carbon intensive, because it takes longer to raise beef cattle (and therefore more resources to feed).

and insect protein is even less than that!

but you'd be hard pressed to find people who would substitute their animal protein with insect protein.

Not sure if it’s the brand, but I tried frozen patties based on insect protein here (in Germany, IIRC the producer was dutch). I was excited to try it, but besides being more expensive than beef, it tasted bland. Now with beef, it’s neither frozen not pre-assembled into patties, so that might also be a difference, but for now I’m holding out for lab-grown meat.