It seems to me like there are some basic ideas for balance. Or .. what balance is.

For instance, 4e tried to actually balance the classes. Everyone could do approximately the same in slightly different ways. I'm sure it worked for some, but it certainly didn't for me.

Other games try to let each class shine in each their area, and this too can be nicely balanced. A game like Dark Heresy might be an example, it feels well balanced to me - although if you include enough stuff, that goes right out the window.

Then there are games that gleefully ignore balance, on a philosophy that .. all the good builds are available to everyone, so if you build something bad, that's not on us. Gurps feels like that to me, but it's a token of all the classless games I know of.

All of the above are fine - or fine-ish - to me. The only thing I have a real problem with are games like 3e, where the game outwardly offers specialized classes - bards, fighters, rogues, barbarians, paladins - but really, absolutely anything they can do, the generalist classes can do better. If you're not playing a full caster, you're essentially doing it wrong. Because anything you'd like to do, a full caster does best.