It’s called aiming. You have to actually fucking point the goddamn gun intelligently. No shit they don’t go down when you don’t hit shit in regards to organs and such.
Listen to any spec ops and they will tell you they pump more rounds into people because simply shooting someone once ain’t gonna make them stop shooting or stay down.
The whole point of the ballistic features is to link the damage calculation to wound tracks which differ by caliber and also armor pen and expansion rate. It’s not just some brain dead shoot once and they’re gone.
The higher tiers don't contain any gear or perks you can't unlock in the base edition, unlike tarkov. Also doesn't lock an entire mode behind the highest tier.
The tiers still currently offer more stuff. If people are willing to buy them for the current price, there's no reason not to have them. I think its pretty unlikely they would add that stuff, seeing how much of their current success is based off of Tarkov making that mistake.