Generally, a Rival is someone who you share goals with and you compete with them to achieve those goals. The player in a Pokemon game has three goals, to complete the Pokedex, to defeat whatever villainous team is infesting the region, and to complete the league challenge.

Silver is one of the only recurring trainers who shares none of these goals with you, so why do you people consider him a better rival than characters like Barry or Hau? Is it because he is a huge dick? Is that the main criterion for "good rival"? He is literally in the same boat as fucking Tierno