When 200 year old technology is still being used, it’s a sign that we got it right over 200 years ago. Even though, technically speaking, in modern alternators, the coils are stationary and it’s the magnetic field that rotates.
The process is extremely efficient, over 98 percent of the input energy comes out as electrical energy in large modern alternators. There is little room for improvement. Some are filled with hydrogen for both its cooling capability and windage loss reduction.
Even the smaller motors and generators, under 500 horsepower, are achieving conversion efficiencies of 95+ percent.
It’s not the only technology that hasn’t significantly changed in over 100 years. Violins still work the same way they did when Stradivari built them. Guns still work pretty much the same way they did in 1900. Bicycles still work the same way they did when the Wright Brothers repaired them.
Some things just defy significant improvement, ok, they are using carbon fiber in the expensive bicycles and synthetic strings on some violins, but that’s a quantum step, not a revolutionary improvement.
By the way, quantum is one of the most misused terms in the English language. A quantum is to energy what an atom is to matter, the smallest possible increment.