I get what you're saying, but let's not pretend the modern world isn't meaningfully different. Artificial light is a big factor, yes. So are odd and constantly changing work hours from a world that now operates 24/7. So is the common expectation of monophasic sleep in general. So is travel and jet lag that we now have to endure, and dietary changes, and stimulants especially for folks who just don't even have 8 uninterrupted hours available for sleep. So are dramatic global temperature changes. The list goes on, and there is more data in this paper https://pmc.ncbi.nlm.nih.gov/articles/PMC11152632/
I can hardly blame anyone for wanting to "hack" or "optimize" their sleep. It seems more necessary now than it has ever been.
I suspect their point was that optimising sleep is relatively simple. Go to bed in a timely manner, keep your bedroom cool, use blackout blinds and sunrise lamps. Don't drink caffeine in the afternoon or evening. It's not rocket science.
I can hardly blame anyone for wanting to "hack" or "optimize" their sleep. It seems more necessary now than it has ever been.