What you're looking for is an EUC, Electric Unicycle. Most of the people in the local onewheel group I'm a member of that ride EUC's wear full motorcycle protection. At least one of them can go upwards of 45 mph.
I am sure that man has many hours of safe riding. It is always the 10 seconds of deadly and uncontrollable trauma that necessitates safety gear. Self-confidence is often the hubris of humanity.
I ride a OneWheel and it can test your nerves sometimes. However, just looking at the speed and stance of a EUC makes me more nervous. You could just open your arms at 45mph and embrace the car in front of you.