The key words in your comment are 3 cars (plural) and 15 years. 15 years is a typical lifespan for one car. And the thing most commonly limiting that lifetime i

The key words in your comment are 3 cars (plural) and 15 years. 15 years is a typical lifespan for one car. And the thing most commonly limiting that lifetime is the engine breaking, totaling the car. My guess is that this will be happening later with a PHEV because you use the engine less. On the other hand the battery will break down faster than in an pure BEV because less battery capacity means also more cycles, which is the thing that will break them down.