It's closer to a do whatever you want game but there are goals to work towards. It's like a super small scope no mans sky with no combat. Super chill and casual.

You're missing out on the fact that the game isn't actually complete. It's labled as a 1.0 release only because all the classes are now out. The full campaign still isn't done and is missing several chapters. The devs themselves mention this.

It's just a problem caused by going online only to protect their cash shop. Helldivers 1 never needed it to play by yourself or with friends.

Too many games release as a GaAs when it doesn't need to be.