Escape From Duckov is an excellent single player parody of Escape From Tarkov, one of the most famous extraction shooters. Duckov was one of my most enjoyed games last year.

Escape From Tarkov itself has the Single Player Tarkov mod which I hear is great, but I don't own that game so can't verify.

I've wanted this since PUBG came out. PvE with a solo focus, teams optional. Could even involve indirect PvP - can't directly attack the other players, just sabotage/score higher. I feel like there's really an untapped market there, but if it's not a live service with monthly payments and cosmetics then the suits aint interested. Gag.

witchfire is in early access but it's a single player extraction shooter that kicks ass. gunplay on par with bungie imo

The Forever Winter seems to have offline single-player.

SwapMeat

There are a few, Red River and Tarkov has PVE mode. I'm also making one but not FPS.

Hmm, does Pacific Drive count as an extraction... wait, there's no shooting. And it's kinda roguelikey. But it's got "spawn in map, do stuff, try to get out" nailed!

It could work. Theres that single player "mmo" on Steam and that actually seems fun. My favorite part is looting everything I can and thats still possible in singleplayer. Maybe if it was just not live service and had PvE elements you could play with your friends it might be really auccessful. But everyone is chasing money printers now.