You make it sound as if it was impossible to have such a marvelous industry without this deep degree of over-optimization. I disagree. The way I see it, with a bit more buffering here and there, it would be mostly the same - perhaps with less bullshit flights that could've been just as well taken by trains (which would be in a better condition, having more business flowing through them), and less middle-men everywhere sucking up the savings from all that optimization.

This is the thing with markets: whatever optimization you make, you won't reap the fruits of it for long. Someone - either competitors or adjacent third parties - will show up to suck out your margin, leaving you mostly as you were, but locking that optimization in as a permanent fixture in the industry. This means that when companies over-optimize, shoot past the optimum "value to profits" ratio and aim for higher margins still, they make the industry permanently (well, until next collapse) worse for everyone.