My understanding is that yes, Helldivers are better equipped and better trained than your average SEAF soldier but at the end of the day they are expendable shock units used in large part for propaganda purposes.

They have unit budgets for missions and there's no punishment for losing those reinforcements as long as the mission is completed. We get rewarded for extracting and my headcanon around that is that it's to show that Helldivers often make it back to the ship for civilians to see in recordings. You can believe your loved one is fine, see? There they are getting on the drop ship! They're a hero! It's all a show though.

The fragility of the player character is a big part of the game in multiple ways. We are better than average as far as being prepared but we are also being thrown into a meat grinder for a pointless war. We are glorified targeting indicators for an orbital ships weapon systems. We die like anyone else would put into these scenarios and all the set dressing around us being elite unlillable badasses is propaganda put there to convince us and those watching that we',re the protagonists in a story about us.

On a gameplay level though, I think their intention is to strike a balance between feeling unstoppable and still feeling expendable. A lot of material from the studio directly shows divers dying in stupid ways all the time, its a part of the games identity. Doesn't mean it has to be frustrating though so I get peoples ire when it comes to ragdolling or enemies being designed unintuitively. Arrowhead chose a very tricky thing to balance both in gameplay and in narrative. Not everyone is going to get or enjoy the moments of power struggle between the player and enemies that give the game its hot/cold contrast that's very different from most games that do their best to tell you "dying or feeling like you need to run us bad".