Tarkov is multiplayer, though in that its you against everyone else. "Winning" isn't predicated on all the other players being dead, so you can form alliances, however I don't think the player to player communication is too great, so any groups are formed pre-game by friends. So its as much of a multiplayer as many of the survival games out there, where its more of a death match with alliances of convenience.
It seems to have more going for it than Survarium did. That was sold as being a multiplayer successor to S.T.A.L.K.E.R., and correct me if I'm wrong, but in reality it was just you being dumped in a small map to play team death match. At least Tarkov has looting elements. Though it'd be nice if Tarkov was less predicated on the PVP side of things and had opportunities to just walk about without being shot from a mile away (S.T.A.L.K.E.R. had breaks from all the action), but that's not what the devs are going for. A pity that vehicles and mounted weapons would probably break the balance as well (that and the maps would make those difficult, not just in size, as there are larger ones, but the amount of intervening junk on the roads).
Given that its a fairly down to earth setting, Spectre seems to fit the bill, along with covering its lethality. I believe Spectre has rules for AI too, meaning you could play it as just you against a bunch of scavs. That ruleset in particular with its aiming to incorporate militia style forces may fit Tarkov better than other modern skirmish games which tend to focus more on just the Special Forces , or at least Spectre has more going for its militias.
Hmn, I may well have a go at running a Tarkov style game at some point. I'd already modified other systems for similar scenarios, so Spectre probably wouldn't be too much of a leap. It'd just need some sort of loot system, though even that could just be objective tokens of a random value which you total at the end of the game (with each model only being able to carry so many based on its equipment - i.e. if it has a backpack / shopping trolley).