IMO the reasons it never took off were:

- Expensive. You can get an electric bike conversion kit for $500 or less, compared to $1000+ for the Copenhagen Wheel. Don't get me wrong, the engineering on the Copenhagen Wheel was amazing, definitely worth the extra money, but it was too expensive for delivery guys to use.

- No replaceable battery: again this rules out delivery guys, as well as all-day rides.

- Requires a smart phone to use it. This was the biggest reason I stopped using my Copenhagen wheel. You needed to use your phone to unlock it or change the speed settings. I don't want to need my phone to ride my bike. What if I lose my phone or the battery dies? What if the server goes down or the company goes under?

I would imagine the common issue with integrated systems applies and makes it expensive: the lifetime and quality of the whole wheel is dictated by the lifetime and quality of the worst part. E.g. the brushless motor may run for years, but a battery cell, or crappy ic breaks in months in bad weather.

I've seen those used on electric kick scooters that are still supposed to feel like a kick scooter, i.e. no throttle lever or controls on the handlebars.

Kostka, the local kick scooter manufacturer sells those: https://www.kostkakolobezky.cz/hill/920-elektrokolobezka-kos...