>>56721349Clefable only saw a usage spike:
A) After Latias dropped down to OU
B) The meta slowed way the fuck down
C) Chip damage became the primary form of damage in the tier, all of which Clefable is immune to
Let's not forget that Clefable had pre-nerf Magic Guard that made it immune to Paralysis on top of everything else it did. After Magic Guard was nerfed in Gen 5 it fell to RU where it's not even particularly powerful. Moltres, Durant, and Druddigon run that tier and Clefable is considered a B-tier Pokemon within that tier.
Gen 6 had more power creep than Gen 4 or 5 did and Clefable shut up to be one of the top 3 Pokemon in OU that gen. It's remained a strong OU pick even through several more generations of massive power creep that have killed off the likes of Garchomp, Tyranitar, Keldeo, Serperior, Tornadus-T, Gengar, Slowbro, Lati@s, ScRotom-W, Thundurus-I, Skarmory, Chansey, and Heatran.
The only other Gen 1 Pokemon with a decent modern track record is Dragonite and that fucker gets buffed every gen. Clefable has only received nerfs since Gen 6 and it's STILL OU.