In my opinion challenger level caps should be lowered to be exactly the same as leaders, because the right now, you can just catch a random pokemon, kill a few lvl 40 Rhyhorn, level it up and challenge any gym with just that 1 pokemon (have it 10 levels higher than the gym leaders) and win EVERY TIME. This is not fun for either the gym leaders or the challengers, so what i propose is that challenger caps get lowered to be exactly the same as leaders, this would make the battles more strategic and would require some thinking, instead of smashing 1 same attack and destroying the gym leader with only 1 pokemon.