In theory, game balance is a fine concept, but it inevitably breaks down in practice. There is a prevalent idea that every character shoould be approximately as powerful as every other character, and that they should be approximately as powerful as the challenges they face. Unfortunately, there are variables in game play which can not be quantified, namely, the players and GM. Every game must achieve it’s own level of homeostasis, and that homeostasis can not be artificially enforced from the outside by a rules manual. It has to be part of the unspoken contract between the people who play the game, and who are presumably friends with one another, and who want to have fun together.
Don’t get me started. There’s a whole rant here that uses some very harsh language, the softest version of which translates to various forms of “crybaby”. “Game Balance” is the fine art of bullying the majority of players and GMs into thinking that something is fair, even when it isn’t.