Comment by pfdietz

Natural gas uses combustion turbines, not steam turbines (except as a bottoming cycle in combined cycle plants, but that produces only 1/3 of the output of the plant).

What combustion turbines allow you to do is avoid heat exchangers, and also operate at a temperature much higher than a steam turbine because no solid material needs to be at the temperature of the working fluid. A simple cycle gas turbine (without regeneration) has no heat exchangers. Heat exchangers are expensive; transfer of heat across a solid/fluid interface is not as fast as we'd like it to be.