Mr. Holmes was prescient beyond his understanding. The "technological change and material growth" Ram Dass describes are a direct result of cheap energy. As the age of fossil fuels draws to a close, it will require a return to a simplicity few can comprehend. (And no, alternative energy sources will not replace oil.)
Put another way by some famous scientist/philosopher dude:
"Any intelligent fool can make things bigger and more complex... It takes a touch of genius - and a lot of courage to move in the opposite direction."
On Mar 14, 2023 Steve Thomas wrote on The Shambhala Warrior, by Joanna Macy: