Watt needed to get a set of technologies developed to make a workable efficient steam engine. E.g. how to bore a straight cylinder in a material that withstands high pressure and temperature.

Another aspect is that solutions tend to occupy a niche within the existing environment. E.g. an iPhone is no use to a Babylonian because they have no 5G infrastructure. A Lamborghini is no use to a Roman because a) no gas stations, although they could probably run it on alcohol, and b) it'd get stuck behind all the ox carts already on the road.