>>548725181. You are expecting little Karen, a little child, to know all of the nuances.
2. You are expecting little Karen to play a metagame outside of the game itself just for the possibility of her Pokémon having a fighting chance.
3. You are locking Karen into a metagame filled to the brim with inactivity.
4. You are not taking into account that online battles don't take into account previously mentioned fan-made metagames any way.
5. You are not taking into account that Eevee is an unevolved form, and as such was designed to be weaker.
6. You are not taking into account that Furret and Flaffy are outclassed by Pokémon with better stats and movepools, and whatever they can do, little Karen could do with other Pokémon-
6. You are not taking into account that Ledian and Magcargo are unable to fulfill even the slightest of niches, because they are terrible Pokémon in all Pokémon games, even spin-offs.
7. Unown.
TL;DR Fan-fic meta will not save little Karen the disappointment that if she wants to win she has to use whatever the metagame requires or whatever is the 'cheapest' option such as minimize spams.