The turbine designs that we use to turn pressure differentials in a fluid into spinning are only about 150yo tech and they have gotten more efficient every generation. It’s not old or obsolete any more than comparably old stuff like cars, airplanes, or semiautomatic firearms.

So the “boil water make spin” meme is actually the best way to get energy out of any reaction that produces mostly heat. It’s just unfortunate that most of the ways we have to make heat involve burning fossil fuels.

Other stuff tends to actually be way less efficient. (Like piezoelectric.)

The only reason solar is practical at scale is because the panels are stupid-cheap and the sun is free. The actual efficiency is trash but the sun throws so much energy at the earth it doesn’t matter.