I've really enjoyed reading all of the comments and examples here. Ebike performance can be very subjective due to rider weight, terrain, weather, tire pressure... so one person's struggle might have been solved or less relevant to another. Please keep in mind that I'm a 135lb (61kg) 5'9" (175cm) athletic build. I've definitely experienced slowdown and struggle on steep hills with low and medium powered hub motors (I try to show this in many reviews), but in practice, I just shift to a lower gear or don't stop half way up the hill, so it has never seemed like a critical issue. I don't own a cargo bike, rarely carry heavy loads on racks or even backpacks. I used to commute to work in Austin, TX by regular bicycle, but I switched to an ebike due to knee sensitivity on hills. I could make it up, and enjoyed the heart pumping! but my knee would hurt.
My experience on a regular bike was massive slowdown at hills and some pain, but I never had to stop... I'd just switch gears. My experience with an ebike was limited or no slowdown at hills and no knee pain and faster more satisfying starts from stop signs

this is the case for me with even a 250 watt hub motor... so the 500 and 700 variants are fantastic, and then the bike weight begins to become a relevant factor because they can weigh almost 50% of me. These are all of the reasons that my current favorite ebikes are any of the
Specialized SL models wit the super-light drive systems, limited capacity batteries, and bike-like frames. They solve my knee pain but give me the feeling of control and agility over the bicycle that I enjoyed from regular bikes. I'm sharing this because my Dad (who weighs more than me) chose a RadRover for himself... He likes the stability and comfort of fat tires, he isn't as worried at railroad tracks, and the power and throttle option are great for him... but he's doing neighborhood and light gravel cross country vs. steeper climbs.