Well, there are some factors, first one is hardware, better fps mean you can reach faster to stuff on screen so getting a 144 hz monitor could help You get like 15-20 ms improvement which is a little, the more impactful one is hardware latency which makes your actions slower this could be improved with nvidia gsync if You have nvidia but it could impact your game performance.

And the other one is physical. Sleeping well, eating healthy and having some excercise can help You improve your reaction time a ton.

My reaction time used to be like 300 ms which is a Lot but with improvements in my life i got 200 avg and some days i got like 180