Yes, my Prius Prime handles highway speeds perfectly fine on battery. In fact, the acceleration is great in pure EV mode.

It just doesn't have much range: only about 25 miles on my 2018 model. Newer models advertise up to 44 miles on EV.

Sure, that's the obvious downside of them. But in the role where they spend ~10h slowly charging overnight from a standard plug, about 25-45 miles is all you'd expect to enjoy in a steady state.

I had a PHEV Honda and I put 20 gallons of fuel in it over 6 years. The system works in the niche for which it was designed.