FWIW, there was plenty of use for pumps earlier on - in mining. But muscle power, then water power, was sufficient.

Part of the steam engine's success was how it contributed to itself - it helped mine coal that would fuel it, and that would fuel furnaces in which steel was made, some of that steel going into... making more engines - and all of that moved around by means of steam power.

*Factorio vibes intensify*

You had to have enough pieces together: demand for coal and steel and moving them distances, sustained long enough to exhaust simple options, and become a problem the steam engine could solve. It was then that the steam engine turned this into self-reinforcing loop, and kickstarted the modern world.