"Pre-industrial workers had a shorter workweek than today's"
https://www.worldcat.org/title/farewell-to-alms-a-brief-econ...
https://press.princeton.edu/catalogs/series/title/the-prince...
Whilst preindustrial societies did see variable subsistence, the floor tended to be higher than today (Clark's introduction, available online, notes that the poorest people who've ever lived, live now, and in great numbers), and cycles tended to be long-term -- decades or centuries, not years. Whilst life expectancy at birth was low, from age of majority it was generally far less abbreviated. Disease was far more prevalent in cities (London was a net population sink well into the 19h century), and major instances of famine and plague something experienced perhaps only by occasional generations within an area, though wth mortality rates from 10-90% (far more typically in the 10-30% range).
You're familiar with Laurie Garrett's wwork on healthxare, and the fact that 85% of mortality decline since 1850 materially predates modern medical practice, including antibiotics, vaccines, and organ transsplants. The Conquest of Pestilence in New York City chart highlights this:
https://object.cato.org/sites/cato.org/files/wp-content/uplo...
My understanding of primitive agrarian societies are that they have hard work, hard lives, poor diet, and a population that is generally at the edge of starvation. (In good times, population grows. In bad times...) You might want to read Guns, Germs and Steel as an example of a reference backing this view up. Or read through random snippets of history like https://en.wikipedia.org/wiki/Great_Famine_of_1315%E2%80%931... and get a sense for the very real struggles that people faced.