Since in electrolysis of water in alkaline medium, Availability of OH- ion is more so Oxygen evolution reaction should not be more sluggish so in this way HER should be more sluggish? Please do
In general, you are right. Water oxidation is more thermodynamicaly favorable at high pH, the reduction is at acidic. Nevertheless, the thermodynamics of water splitting is pH undependable, ~1.4 V. However, there is no straightforward dependence of kinetics on thermodynamics.