guys 144hz or 75hz

The Hz rating of the monitor has nothing to do with competitive esports games. Higher Hz rating just reduces tearing, a cosmetic thing. People were playing competitive "esports" games before high refresh rate monitors.
 
@gasaraki a higher refresh rate is one factor that can reduce total input lag (time if takes for an action to appear on screen), which is why it's often talked about for competitive gaming. I mean, the difference between a 60 Hz and 144 Hz monitor would be less than 10 ms (everything else being equal), so I'm skeptical how much difference (if any) it really makes, but some people feel it matters.