It may also be correlated with the population, though. Specifically the working age population.
I imagine that, as populations decrease and you have fewer people available to actually do any research, technological advancement also stagnates and slows down. If populations ever start increasing again in the future, then I imagine technological development will grow as well
Damn, imagine the levels of segregation, speciesm and genocide we would see if other human species had thrived and grown like us.