SURPRISE!, they weren't...
Gamefreak simultaneously gives a mon enough hp that pumping full investment can kill a large swath of pokemon with just final gambit alone, literally as a last resort.
Because of the hp investment, it is really difficult to take down in one go, meaning it inevitably feeds into the rage fist stupidity. +50 for every fucking hit... and it doesn't reset on switch. You mean to tell me this is the same gamefreak that has my boi Regigigas still have Parkinson's in his ability slot that resets on swap... fucking wow.
Add that to it being a very good type, ghost imo is the new dragon, it is way to strong for little to no counterplay, it needs another weakness, I still think psychic and ghost should have a rivalry, both are super effective against each other, opening more counterplay to ghosts, which has 2 IMMUNITIES, for 2 weaknesses, dark and GHOST ITSELF, real dragon type energy there.
The only thing of note is it technically lost speed when it evolved, but 5 speed and base 90 is still wicked high for this mon with what it packs.
Rage fist needs a nerf hard though, there is no reason a move should ever stack based on X circumstances, it is just unhealthy if it is good, and just gimmicky if not, both not fun to play against.