Yep agreed about gear etc , like SPT mod for Tarkov and indeed Tarkovs own pve mode all gear or progression you get is only for pve.
But there are plenty of popular pve extraction games to be fair so i dont see why it wouldnt work.
The desire for a pve mode seems to be gaining traction according to some YTers and redditers.
Grayzone Warfare pve is excellent, its far from perfect with dodgy AI that are improving with every update.
Incursion red River also very good but very early in its life.
Witchfire does it better than any pve extraction game imho, what a brilliant game.
Then there are the likes of Deep Rock galactic and Helldivers pure PVE with extraction, i know its not the same but i dont see why it wouldnt work.
Anyone remember the Hunters in the Division 2? They were insane fun to fight but rarely made an appearance sadly.