>>40181371Mega forms had their own individual designs, stat distributions and Abilities, which have now been lost.
Z-Moves had various applications depending on what Move was being powered up. Me-First and Stockpile both use Normalium Z, but have different side-effects. With Dynamax, everything becomes Max Strike/Flare/Geyser/etc. based on Type.
They took these mechanics and completely diluted them. And hey, it might for a healthier meta. But it is goddamn boring as a concept.