Irl, a suppressor has little to no effect on a gun’s recoil (though this can vary from gun to gun). It does reduce it by a little, but nowhere near as much as it is depicted in Tarkov. Not to mention how unbalanced it makes the suppressors in this game as there is never any question on whether you should run a suppressor or muzzle break. Sure the suppressor is more expensive, but when the availability of the two options are the same you won’t ever see someone choose a muzzle break over a suppressor.
Another thing suppressors do is actually reduce the accuracy in weapon’s they aren’t designed for. For instance, running the KAC suppressor on the RD704 irl will result in massively decreased accuracy and muzzle velocity. This is because the KAC suppressor is designed for 7.62×51 which has a LOT more pressure coming from the cartridge.
Overall, the suppressor system should really get another look next patch. As of right now, they are waaaaaaaaay over-tuned compared to reality.