I believe that the ultimate…
I believe that the ultimate refinement or evolution of the hybrid will be the transition from an ICE drivetrain to an electric drivetrain with various forms of energy supply (battery, capacitor) and onboard generation (fuel cells, turbines).
Wrightspeed developed a hybrid platform using an electric drivetrain with a small battery powered by a natural gas turbine. This was developed as a retrofit for trucks and buses.
Turbines are the most efficient fuel burning technology and driving a constant torque generator is more efficient than driving a heavy chassis.
EV drivetrains are, I agree, the future.