Specifically, for many hard-tech startups that do not require extremely sophisticated technology, if the first inventor had not existed, how much later would someone else likely have done something similar?

By “hard tech that does not require extremely sophisticated technology,” I mean physical products that could be created in a typical local makerspace (i.e. without specialized nanotechnology, advanced fabrication methods, etc.). For example, smart thermostats and basic robotics would fall into this category.

I would like to believe the answer is often “years later,” but I can also imagine the delay being only a few days to a month, because i) many hard-tech founders are actively looking for startup ideas; ii) many of the underlying problems are already well known; and iii) if the technology is relatively accessible, it seems especially likely that multiple people would try to solve the same problem around the same time.

Is this intuition correct? I'm looking specifically for rigorous quantitative analyses that try to estimate the “delay” for accessible hard-tech startups, not one-and-off anecdotes. If anybody knows of any such analyses, it would be deeply appreciated.