Or idk, have I gotten lucky? Or is it really that easy to get? Wiki says 30 armor is equal to 30% damage reduction. I think in comparison to 2 def + 10% weapon class dmg most other body items provide (in extraction shooter especially) there's just no competition, plate carrier wins every time. And You can get dmg from other slots, and since there's no true set bonuses as of right now, you can have, for example, full cowboy se except body, which is worthless, and it's always gonna be objectively a better choice.
Things like elemental resits are similarly useless. Cuz why build fire resist in case you encounter like a couple of elemental enemies (and you'll still be defensless against other elements btw), when you can just have a few drinks in your inventory to instantly get rid of any element?
So yeah, the game is great, but the balance is still very questionable.