Its also kinda lazy though.
And im not sure it really needs to be explained. I mean the Golden Age had all the Amazons at the same general power level but established that Diana worked harder, trained harder, studied harder, and believed in herself which made her the second strongest of all the Amazons.
I don't see Superman writers straining to come up with an excuse why the fifty or so other Kryptonians fluttering about are not as strong as he is. Nor why any rich boi is as capable and unstopable as Batman (whose established to somehow be able to just beat up anyone for some reason?) They simply say 'because' and just move on