They are fine on dedicated cycle paths, but I'd feel very vulnerable to being squished riding in urban areas. People can't drive for shit and the low height makes you less visible to trucks and SUVs.
This might be very specific to the US. Here in Europe, SUVs aren’t nearly as prevalent, and trucks don’t drive on the same roads as cyclists do. In my experience, when I'm going 30km/h, I’m no longer a roadblock for cars.
However, bike paths aren’t designed for the kinds of speeds you'd get with that thing. I'm driving an e-bike, and I have to brake to a near standstill whenever I get to a bend in a bike path, because for some reason the planners think that bikes can turn on a dime. Also, in my city we have a lot of mixed bike/pedestrian paths, and pedestrians don’t appreciate it when you drive by with 30km/h within a few centimeters. I've also had people who froze like a deer in headlights when I approached.
