>>55817972>in many ways unfair and RNG basedThat's just the nature of battling in general. When the opponent is on a similar level as you, meaning they have max EVs, nonzero IVs, good moves and so on, RNG like crits and hax items play a larger role. People also tend to remember the times they get haxed to death instead of the other way around.
If you know the Battle Frontier's mechanics that determine how the Pokemon sets are chosen, it helps a lot. It's pretty much all documented somewhere.