>>49413493That has nothing to do with the exp share and more to do with Game Freak making every challenging aspect of PLA optional and rather easy to avoid.
Alpha Pokemon spots you? Just sidestep them
Frenzied Pokemon wreck your Pokemon with multiple strong moves in one turn? Just don't battle them with Pokemon
The only actual mandatory "challenge" of PLA is the final Volo battle, and there are many ways to bypass that difficulty as you'll have enough resources to "easily " catch Alpha Pokemon. Alpha Garchomp destroys most of his team, and Alpha Blissey walls Giratina with little effort.
Changing exp yields wouldn't change the fact that Pokemon (as how Game Freak designs it) is exploitable.