Yes, I know there’s evidence of our grand-grandparents routinely sleeping in more than one stretch, and waking up in the middle of the night for prayer, food, sex, or some other activity.

It was just an example. What our ancestors did not do nearly as much as we do today is shifting their waking and sleeping hours, crossing time zones, creating artificial daylight, using chemistry and technology to alter those cycles, etc.

My point with “these changes seemed outrageous in the beginning” is that newspapers have a long history of alarmed articles and op-eds ridiculing, and denouncing the dangers of, all sorts of technological and societal innovations.

It was said that travelling faster than a horse gallops would kill people. The railroad would “endanger passengers and set fire to crops”. Aeroplanes, light bulbs, computers and the internet were dismissed as vacuous fads. The printed press would isolate readers and endanger the practice of getting one’s views from the pulpit. Video Killed the Radio Star. Et cetera.

As Douglas Adams put it:

“I’ve come up with a set of rules that describe our reactions to technologies:
Anything that is in the world when you’re born is normal and ordinary and is just a natural part of the way the world works.
Anything that’s invented between when you’re fifteen and thirty-five is new and exciting and revolutionary and you can probably get a career in it.
Anything invented after you’re thirty-five is against the natural order of things.”