>>33623826Except Gen 5 had arguably the hardest and best thought-out Gym Leaders of the series, each with their own strategies. Like Roxie's Venoshock fuckery, or Elesa's Volt Switching. (Relatively of course, Pokémon isn't hard)
The problem isn't the 3 Pokemon limit, because usually Gym Leaders only have one Pokémon that's a challenge anyways, the rest being fodder.
It's just making the battles uninteresting and bland, which was a big problem for me in X/Y. I actually think the boss fights with the Totem Pokémon are a big step forward in this aspect, with lots of different strategies coming from the use of the ally Pokémon, but its taboo to praise Gen 7 here, so.