I'm not well versed in physics, but when I think about the fact that electric motors haven't changed all that much it sort of makes sense.
Inducing a current by moving something in a magnetic field, or vice versa, may seem like simple designs, but perhaps that's why we haven't replaced them yet. Rotational motion seems easy to service and efficient.
Same with water being particularly easy to turn into a gas using heat, as well as being super plentiful on Earth. There are just a lot of things going for a steam turbine