Why do polar protic solvents have little effect upon SN2 reactions?

Small impact? Who said that?

They inhibit SN2 by solvating smaller nucleophiles.

Indeed, they sterically impede the nucleophile's ability to attack the electrophile through nucleophilicity in the coordinated mechanism.

Polar protic solvents have little effect upon SN2 reactions because they tend to solvate both the nucleophile and the leaving group, reducing their reactivity. Additionally, the hydrogen bonding capability of polar protic solvents can stabilize the transition state, slowing down the reaction. Therefore, SN2 reactions generally proceed more slowly in polar protic solvents compared to polar aprotic solvents.

Polar protic solvents have little effect upon SN2 (substitution nucleophilic bimolecular) reactions because they tend to solvate both the nucleophile and the leaving group equally. This means that the solvation of the nucleophile and the leaving group does not significantly affect their reactivity towards each other in the SN2 reaction. Additionally, polar protic solvents can stabilize both the transition state and the reactants, leading to a minimal impact on the reaction rate. Therefore, SN2 reactions proceed relatively unhindered in polar protic solvents compared to polar aprotic solvents where solvation effects may strongly influence the reaction rate.