much more sane Helldivers headcanon that’s based on more than “I just kinda felt like it lol“:

you (as the player) aren’t actually a helldiver, rather you are your super destroyer’s onboard AI that controls the helldivers. This could explain why even if “you“ die you can still spectate and see the UI, and maybe an explanation on why this AI isn’t an enemy-of-democracy killing machine is that they have to rush production and don’t have time to train the models beforehand, other than the helldiver tutorial.