Half life and radioactive dating mastering physics
Pre-hominids seemed more primitive than prehistoric humans who had tamed fire.Natives armed with spears and arrows seem less technologically advanced than invaders armed with firearms.Steam power seems less technologically advanced than nuclear energy.So naturally historicaly-minded people tried to codify this into a scale of technological advancement, to conveniently classify various cultures at various times in their history. Since many early researchers were regrettably Western-centric, they tended to visualize tech levels as a linear path (that is, the path followed by Western civilization). Latter researchers studying a wider range of cultures (such as China) realized the linear path was a poor model.There is no particular reason why Louis Pasteur's germ theory of disease was formulated about the same time as the invention of the Gattling gun.
So culture Alfa might have germ theory tech at the same time as gattling gun tech, but culture Bravo might develope gattling guns decades before germ theory.
The convoluted way that tech advances influence each other was the entire premise behind James Burke's documentary series Connections and The Day The Universe Changed, which you should watch if you haven't already. The tabletop boardgame Civilization popularized the use of tech trees in 1980.
And pretty much every 4x game uses tech trees, with the items accessed by investing in tech research."Technological advance is an inherently iterative process.
One does not simply take sand from the beach and produce a Dataprobe.
We use crude tools to fashion better tools, and then our better tools to fashion more precise tools, and so on.