Earlier quoted context omitted.
But how often do you have issues with the engine. My last 3 cars never had a single engine issues for at least 175.000 miles. Its very rare today to have big engine issues.
It's the powertrain that's far more apt to be the problem. Hence a plugin hybrid generator style should be far simpler than a system with both an ICE and electric powertrain.
I know the Chevy Volt had an all-electric power train, and the ICE is purely a generator that dumps power into the electrical system, and the Chrysler Pacifica Hybrid has a dual power train, but I wasn't able to find a concise list of which hybrids have taken what strategy.