He has been biten by an different spider whose genetics are little bit different from Peter’s Spider.
Even he has been biten in the age of 14 so he has more potential in his power than others spider heros.

Miles morales belongs to other timeline or universe and in every universe we have the same people but different skills or behavior or powers this can be a reason or the other reason could be the one said by mystery020

He from the timeline . Every person has his power s and skills in all university

His powers are not more rather they are different

He cant climb wall like other spidermans but can create static shocks