That ain’t no bull
Everyone has their theory on how to be the best Pokémon trainer in the world. If you ask me, I’d say use that Charizard to obliterate anything that dares to challenge you. Work smarter, not harder.
To coincide with the re-release of Pokémon Blue and two other games that aren’t as good because I didn’t have those ones as a kid, The Pokémon Company has put out its objective findings on how to kick some Poké-ass. In short: Get yourself a Tauros. He’s fast, he’s versatile, and he does bonus damage.
It’s an interesting read and well worth your time. It breaks down some specifics of battle mechanics, and lists more Pokémon to focus on and how to train them. Although, Charizard isn’t mentioned once, so maybe you don’t want to take The Pokémon Company’s report at face value.