A "wide range" of RPM is completely relative. Even Teslas have carefully tuned torque curves and efficiency ranges. The only reason a Tesla is such as speed monster down low, is that they start out ludicrously overpowered and give up the top end completely. That's not to say they aren't adequately "fast", but given the performance metrics below 100mph, they should be Bugatti-eaters on the track above it, and they are far from it. They are actually VERY slow above 100mph by supercar standards. And the efficiency at both very low and very high speed is quite poor, and the Tesla REQUIRES active battery cooling systems and complex BMS to keep from total nuclear meltdown when driven hard.
Translate that to a tiny bicycle motor and controller at todays level of technology, and that same performance range drops dramatically. We simply cannot add the weight and complexity of the systems that make a Tesla a decent (but still limited) wide-range performer, so we are stuck using traditional gears for the foreseeable future. Bike tech is going to be a long ways behind the best e-vehicles, and the fast charging needs to truly extend our range even farther, so real efficiency is still a long way off. That's not to say the future isn't bright however. It's a pretty cool time to be alive - technologically speaking.