>>29337153Because usage is only a tool to move weak Pokemon DOWN to lower tiers where they're viable to compete, not UP to higher ones. OU is the center of the structure, with Ubers being the banlist for it and every tier below it being things that didn't get enough usage for OU.
If you're suggesting bans should entirely be based on usage, and that Ubers become a usage tier, it still doesn't work for the same reasons ban tiers exist.
1. A Pokemon can be very high in usage while still not being broken. As much as /vp/ will tell you otherwise, Landorus-Therian will never be OU banworthy, but its usage is very high.
2. Pokemon can be very low in usage but also be broken. Gen 4 Wobb is a case of this- it was very nearly UU by usage when it got banned. It really was only broken in the context of very high ladder and tour players, but that's really the context which Smogon balances around, so even if Wobb was only broken in the hands of <5% of players, it's still broken.
3. A Pokemon can be terrible in the tier above it while absurdly broken in the tier below it. Most OU bans fit this bill, and would alternate between being dropped and raised every single tier period. Basically, 6 months out of a year a tier would be unplayable because the thing that's broken in the tier dropped since it's unusable in the tier above it.
