PHEVs are (largely) for consumers who don't understand how EVs work (but think they do) and are too scared of having to sit in their car and charge for an hour anytime they leave the town perimeter.
In reality with most EVs, you can drive 500 miles with one 30 minute charge. That's 7 hours of driving at 65mph, and one 30 minute charge. I know everyone claims to be a psychopath driver who never stops on a road trip for more than 5 minutes every 7 hours when they learn this, but the reality is you don't even notice the charging stop. Unlike gas pumps, it's the norm to leave your car on the charger while you go do something else (eat, sight see, shop, w/e).
It's only really trips that are >500 miles where this starts to become apparent. Or on trips through remote areas. Or having no idea how EVs work, driving till you're almost empty, then deciding it's time to get off the highway and find a charger.
The consumer segment that actually needs PHEVs is incredibly small, but the segment that thinks they need them is huge, hence the market.