Here's why:
* PokeRus is a beneficial condition: It doesn't make your Pokémon sick, it actually increases the rate at which they gain EVs (Effort Values) which determine their stats.
* It's a temporary status: PokeRus will eventually go away on its own. You can't force it to go away, but it's not something you need to be concerned about.
If you're looking for ways to increase your Pokémon's EVs, there are other methods besides relying on PokeRus:
* Strategic battles: Defeat Pokémon with specific stat-boosting moves to gain EVs in that stat.
* EV-training items: Items like the Power items (Power Weight, Power Bracer, etc.) can be used to gain EVs in specific stats.
* EV training areas: Some areas in the game are designed for specific EV training (like the Strength training area for Attack EVs).
So, enjoy the benefits of PokeRus while it lasts, and don't worry about trying to cure it.