I’d just have to remember to get the engine to start once in a while.

I can’t speak authoritatively about every PHEV, but the one I have at least takes care of that for you and will run the engine at least once every three months or so if your regular driving habits are such that you manage to stay all electric all the time.

That said, if your driving patterns are such that you can go 3+ months on the 40 mile EV range without ever dipping into the gas tank maybe you don’t need a PHEV.