Eevee just sucks
Even with a fairy eeveelution and actually some decent stats, the best it could go is UU. The fact that like 3 base stats are in the sixties make it super unviable in the OU metagame. Hell, most of the eeveelutions are in the complete lower tiers, like NU. Baton Pass got completely yoted by Smogon, so it's most viable set got taken away from it. And every single eeveelution, except maybe Sylveon, gets completely outclassed by some other mon. It's a jack-of-all-trades / master-of-none sort of mon, and its movepoll just sucks.It's a darn shame too, cause I actually like the eeveelutions.