The current COVID-19 pandemic suggests a mechanism. A sufficiently contagious and deadly pathogen could prevent larger groupings of people from forming stable societies.

Smaller groups would continue to survive in isolation, but any attempts at communication from larger gatherings or permanent habitation would result in an outbreak that would return the population back to the pre-industrial state.

This could be repeated until a form of remote communication with sufficient incentive to drive development could be managed as desired.

An alternative mechanism is a sufficiently complex solar system like the one in Jerry Pournelle's Janissaries that triggers reversion back to a tribal society periodically.

The current COVID-19 pandemic suggests a mechanism. A sufficiently contagious and deadly pathogen could prevent larger groupings of people from forming stable societies. The recent large outbreaks of Ebola virus disease provide similar examples as population sizes grow, the possibility of severe epidemics increases.

Smaller groups would continue to survive in isolation, but any attempts at communication from larger gatherings or permanent habitation would result in an outbreak that would return the population back to the pre-industrial state.

This could be repeated until a form of remote communication with sufficient incentive to drive development could be managed as desired.

An alternative mechanism is a sufficiently complex solar system like the one in Jerry Pournelle's Janissaries where predictable, if unlikely, orbital mechanics trigger reversion back to a tribal society periodically.

The current COVID-19 pandemic suggests a mechanism. A sufficiently contagious and deadly pathogen could prevent larger groupings of people from forming stable societies.

Smaller groups would continue to survive in isolation, but any attempts at communication from larger gatherings or permanent habitation would result in an outbreak that would return the population back to the pre-industrial state.

This could be repeated until a form of remote communication with sufficient incentive to drive development could be managed as desired.

The current COVID-19 pandemic suggests a mechanism. A sufficiently contagious and deadly pathogen could prevent larger groupings of people from forming stable societies.

Smaller groups would continue to survive in isolation, but any attempts at communication from larger gatherings or permanent habitation would result in an outbreak that would return the population back to the pre-industrial state.

This could be repeated until a form of remote communication with sufficient incentive to drive development could be managed as desired.

An alternative mechanism is a sufficiently complex solar system like the one in Jerry Pournelle's Janissaries that triggers reversion back to a tribal society periodically.