Being good at a game, especially with a game as broad as this one, with fight designs being as inexhaustible as they even, be it at any level. Just makes it come down to an experiential thing more than anything else. Or just being an adept problem solver.

The more you practice a fight, the better you'll get at the fight, the more consistent you'll be with the fight, and you eventually clear the encounter. Anyone can clear any given encounter in the game given time. Doesn't make them good at the game. There's scarce a few people that are genuinely good at this game. A lot of other people are just good at following instructions and guides.