Frankly, as a old-school Pokémon veteran (Gen1 baby!), I’d be less bothered by the built-in ExpShare function if it didn’t completely fuck with the progression balance. Shit’s not even a challenge anymore. I don’t play Pokémon to catch 'em all; I never have. I play Pokémon to develop a bond with & complete a journey alongside my party, not swap out new party members every other town.
And without a challenge there can’t really be much of a journey to overcome, can there?