superpower's point isnt to hit mega aggron, it is to OHKO chansey, umbreon and some empoleon, who can cripple crawdaunt; hydreigon and opposing crawdaunt, who can tank a hit and KO; and other mons that are rare but also have niches, like ferroseed; aerial ace's only utility is chesnaught and some heracross (and virizion, which isn't used). also, hydreigon and mew have zero counters too, in theory, and they're relatively far from being banned.
also, i've been using absol and it's being underwhelming so far (whats the best set? i might be using it wrong), while specs analytic magnezone is being absurdly strong, i think it's as broken as crawdaunt
But Chansey isn't OHKO'd by Superpower, knock off and crabhammer both 2HKO as well, same with umbreon and empoleon.
252+ Atk Life Orb Crawdaunt Superpower vs. 252 HP / 252+ Def Eviolite Chansey: 468-551 (66.4 - 78.2%) -- guaranteed 2HKO
252+ Atk Life Orb Adaptability Crawdaunt Crabhammer vs. 252 HP / 252+ Def Eviolite Chansey: 390-460 (55.3 - 65.3%) -- guaranteed 2HKO
252+ Atk Life Orb Adaptability Crawdaunt Crabhammer vs. 252 HP / 252+ Def Umbreon: 200-237 (50.7 - 60.1%) -- 85.5% chance to 2HKO after Leftovers recovery
252+ Atk Life Orb Crawdaunt Superpower vs. 252 HP / 252+ Def Umbreon: 239-283 (60.6 - 71.8%) -- guaranteed 2HKO after Leftovers recovery
-1 252+ Atk Life Orb Crawdaunt Superpower vs. 252 HP / 252+ Def Umbreon: 161-190 (40.8 - 48.2%) -- guaranteed 3HKO after Leftovers recovery
(and doesn't umbreon prefer running sp.def?)
252+ Atk Life Orb Adaptability Crawdaunt Knock Off (97.5 BP) vs. 252 HP / 252+ Def Empoleon: 224-265 (60.2 - 71.2%) -- guaranteed 2HKO after Leftovers recovery
252+ Atk Life Orb Adaptability Crawdaunt Knock Off vs. 252 HP / 252+ Def Empoleon: 151-179 (40.5 - 48.1%) -- guaranteed 3HKO (2HKO's after first knock off)
252+ Atk Life Orb Crawdaunt Superpower vs. 252 HP / 252+ Def Empoleon: 278-328 (74.7 - 88.1%) -- guaranteed 2HKO
Adaptability makes his stabs so strong that they're almost a always a better idea than using coverage, unless the opponent resists both, that's where AA comes in. Yes AA is only good for Chestnaught and certain other fighting and grass types but when that's one of the only things that can confidently switch into you, then AA is better.
All you get for Superpower is really hydreigon, which isn't much since all of them out speed you anyway, you wont have a chance to finish the job before it roosts, if it is even running defensive.
And Chansey counters Hydreigon, even adamant superpower can't take her out.
252+ Atk Hydreigon Superpower vs. 252 HP / 252+ Def Eviolite Chansey: 328-386 (46.5 - 54.8%) -- 64.5% chance to 2HKO
Mew is special because it runs so many things, but the issue is its not all that threatening, 100 offenses are starting to lack and the pure psychic type does it no justice. The status happy sets are dealt with by status absorbers and the sweeping sets... like I said, its offenses are lacking. Jack of all trades, master of nada.