I had 75 hours in RDR2 and I've never thought the game was heavy on or promote mass collecting stuffs. Sure you can search each dead body after a fight for ammo and some changes but... why should you? If you want to make money, go hunting, do bounties, rob banks, sell horses, sell treasures. The only items you should take are moonshine, potions, food and cigarettes which often are placed neatly inside cabinets, the game's pacing is slow enough that I don't find the animations interrupt anything.
Also I love skinning animals, feel especially cathartic and satisfying after a long hunt. Walking over their corpse and spamming E just wouldn't feel the same.