Other people have talked about this, but I'm wondering if the change to having electric drive motors and an engine just for generating electricity is more efficient and easier on the engine. (regenerative breaking aside)
Most hybrids use a slightly different engine, which is more efficient but generates less force. The hybrid transmission can add torque when accelerating or going uphill.
The engine must get less wear. My Camry Hybrid only needs an oil change every edit: 10,000 miles.
My Camry Hybrid only needs an oil change every 5000 miles.