Hi everyone, there are a few good reasons for not banning Kyurem in PvP:
Ability to counter a wide range of types: Kyurem has a wide range of moves, with the ability to learn Dragon-type, Ice-type, and even moves like "Focus Blast". However, its power is still limited by factors like speed and type weaknesses, such as Steel-type against Ice or Fighting-type (against Ice).
Not too strong compared to other metas: Kyurem is not a "dominant" Pokémon compared to other names like Azumarill, Lopuny, etc. These Pokémon are often stronger in PvP thanks to high defense or flexible moves. Kyurem can still be countered by many popular Pokémon in the meta.
Strategy and diversity: Banning Kyurem can limit the diversity of PvP strategies. Because it is not always the optimal choice, players need to consider factors such as speed, attack, defense, and move set. Allowing Kyurem to exist creates opportunities for creative strategies and increases the variety in PvP.
Easily countered: Kyurem is powerful, but there are Pokémon that can counter it very easily such as Metagross, Mawile, Scizor. This proves that it is not too "overpowered" to need to be banned.
So Kyurem is not strong enough to make it a fearsome opponent in PvP. Banning it could take away an interesting strategic option that players could use.