The only place it really shone rather than being just fine filler was white weenie lists
In MTG, blue cards are wizards and faeries and monsters of the deep, counterspells and illusory tricks, magic that accumulates knowledge and incremental advantage and undercuts, rather than directly opposing (brains over brawn and mind over matter)
Historically that's exactly the kind of behaviour that gets the Pinkertons called on you
Hopefully, youre not trying to play the Purple Sengoku deck at max rarity because youll have to spend way too much money on a playset of each of the Admirals
Outside of Commander, Birgi has made a name for herself in Standard, Pioneer, and even Modern, as she's even better than more traditional cost-reduction permanents