>>21292607This. Plenty of good Pokemon are in UU because they don't see enough standard usage, and that's fine. Arguably better for them.
Take Mega Pidgeot for example. Perfect accuracy Hurricane outside of rain is a wonderful thing, even if it doesn't get any other new toys. Powerful move, no recoil or drawbacks, an confuse. What's more, it is a unique niche, which is always good for viability. Heat Wave is a decent coverage option, leaving only Rock types to stand in its way, though they are definitely a hard stop. Depending on how its stats shake out, it might be perfectly effective in OU, but it isn't going to be effective ENOUGH to warrant taking up the coveted Mega Slot. Why use it over Charizard, Heracross, Pinsir, or Tyranitar? So, in this scenario, it ends up in UU. Now it has far less competition for a spot on the team, and the overall power level of the metagame around it is a bit lower. It is more effective, it can perform better, run around more freely, and you're still more than welcome to use it in OU if you like. Better than being OU by usage but not being too stellar there, or banned to BL where if sits in the twilight zone.
This applies all the down the ladder, but is particularly applicable to the OU-UU boundary. There are some incredible powerhouses sculpting the standard metagame, and plenty of fine, useful Pokemon are outclassed, hard-countered, or even just crowded out by the cut-off percentage. UU is far from "shit" tier.
