The thing is absol makes opponent over commit energies for retreat then leaves them with less when you take a Return KO AND it's a basic as opposed to alolan muk which not only makes it easier to get it's effect, but also takes less deck space too.
Like it really slows down normal and ultra Mally. Slows down all decks playing the jirachi escape board line and just slows down decks that rely on only losing one energy on a basic to retreat
Blacepphalon doesn't care about it
ZoroRoc doesn't care about it
Malamar can play around it with Malamar's Psychic Recharge and running a bunch of switch cards
It's not that Absol is bad, it's is good. But I think you're really overstating how effective Absol is against the meta
Finding an answer to the meta is the central challenge in deckbuilding in this game, solving it is how you win tournaments.
I don't think Absol's it right now though, even with high counts, 'cause switching cards are everywhere in decks that actually want to move their pokemon. Not that it's necessarily bad, I'm sure whiffing a swing turn can matter in some matchups, but I don't think it's the big secret that'll let someone take the next regional.