Balance is needed to prevent certain characters from overshadowing other characters in major portions of the game. Being consistently overshadowed often leads to people feeling worthless, bored, or frustrated and often lead to them no longer playing the game in question. While poor balance can sometimes be overcome by the DM changing up their game to set aside a special time for a certain character to shine, I imagine this puts a lot of extra stress on a job that is already stressful and might possibly lead to hurt feelings on the part of the player who needs to be given a special chance to feel like they are contributing. The developers providing for good game balance at the start, makes it so the DM doesn't have to do the job of the developers on top of their already difficult job of DMing.I find it bizarre that you quoted where I talked about "2E being mid-life" and then quote articles from 1984 and 1978. 2E came out about 1989, and was mid-life in 1994 or so, 10-16 years AFTER the articles you cite.
There's not a whole lot more to say. This level of historical chrry-picking is pretty normal when people can't get it through their heads that "Balance" is not axiomatically good. If you want to argue for a "balanced" system, you have to establish why it's needed. You don't get to assume it. Period. That is not open for debate.