>>13058772Fairy is only weak to Poison and Steel, the first would be an immunity and the second is neutral but nobody attacks with that anyway.
It trades a weakness to Fighting for immunity to Dragon and the ability to do STAB super-effective damage to Dragon, Dark and Fighting types. Additionally, its Steel typing means it also gains STAB super-effective damage against other Fairies.
There's also the possibility that Fairy turns out to actually have resistances, which would just make this trade better.
