I also 100% agree to this. As of now the current implementation of co-op doesn't deliver a 100% optimised experience.

My biggest issues that I have with the co-op feature,

1. Total co-op players should increase to at least four friends instead of only two.
2. Progress should be saved and equal for all players not only the host.

I got this game recommended by friends to do co-op together. Four players in total licenses of 239,96 euro. Don't get me wrong it's beautiful game but for our group it's sad to see that this in my opinion not fully implemented as did expected it.

That said it still a maginificant single player game.

Hope that this feature will be improved upon in future versions.

Regards.