Hmm. Mainly that access to much larger quantities of energy than before in the form of oil/coal/gas enabled the creation of a much more complex system than before, with a higher metabolic need.

Ongoing servicing of that metabolic need requires continuous access to the same or greater amount of energy year after year. The world burns through its annual resource budget in July this year.

As we continue to extract more and more, the energy return on energy invested goes down, so net energy availability drops, making it harder and more expensive to continue the current basal metabolic rate, let alone fueling continuous growth. Because so much is built atop the energy mechanism, instability happens when it's threatened or changed.x

So maybe a better turn of phrase would have been that it's the first time we've harnessed so much energy at once and effectively put a lot of energy slaves to use per each person. Like starting to use fossil fuel to create fertilizer that enables more people to survive famines, you create a scenario where you need ongoing access to the same or greater amount of energy just to keep up. Not saying it was the wrong choice, just that we tend to fix issues by making more complex solutions that introduce future resource need.