2020 plug-in Hybrid

I might be buying this car over the next few days:

2020 Toyota Prius

1.8 VVT 8.8kWh Excel CVT Euro 6 (s/s)

For £18k

44,000 miles on the clock.

It's a plug in Hybrid but a car dealer told me that people generally prefer the non plug-in hybrids. Is this true and if so why?

Is the plug-in Hybrid not just everything a Hybrid is and more?