BTW if you’re planning to buy an ebike, I have some advice… I strongly recommend you get a bike with a “torque sensing” drive. Most cheaper ebikes have what’s called cadence sensing. That means that as soon as you start turning the pedals, it slams into 100% power for whatever speed you’ve set it to. I really despise that jerky behavior, and it caused me to wreck the ebike I was riding five years ago. You also tend to not get much exercise, but just ride the bike like an electric scooter.
That certainly doesn't match my experience with my bike. And that matches up with some misleading and/or misinformation I've read elsewhere about cadence sensor ebikes. They aren't all the same.
I have a cadence sensor ebike. It does not have "speed settings". It has assist levels, and these are associated with power levels (watts), which I can program for each, and it is NOT associated with any speed (mph), like a cruise control. Speed only comes into factor when hitting the legal 28 mph assist limit, where it cuts the assist power.
It also only applies the amount of power selected by the assist level. So when I go into assist level 1, that's about 50 watts. It absolutely does not go to 100% power, which is over 1000 watts with a fully charged battery in the highest assist level when set to 100% (it's customizable for each level on my ebike). There's no jerking to speak of when I'm riding. And there's a power ramp up to also reduce any jerkiness if the assist level is set for high power. So, that's been a non-issue.
And that part about not getting much exercise is a laugh. It sounds like this had something to do with your specific ebike, or you didn't know how to use assist levels, or maybe, as with some crappy models, it actually assisted based on speed instead of power. On my cadence sensor ebike, I use a low assist level, sometimes 0, often 1 to 2, and I pedal with force to maintain speed and keep my heart rate up, working up a sweat. In a nutshell, I can get exactly as much exercise as I want to. And it's helped keep me in shape just as with my standard bike in the years prior to that. I never ride it leisurely or "like a scooter".
My ebike is a Ride1Up 700 series which has a cadence sensor and current/power based assist, not a speed / cruise control type of assist.