It's not quite the same thing, but there are many self-propelled wheeled contraptions when balance is a concern. Standard and hand propelled trikes are safe. Some even provide bucket seats with seatbelts. There is a bit or risk of tipping in sledges, bit most people are fine going straight and slow. (Users are also strapped in to reduce the chance of injury.)

It's basically a trade-off: it is exchanging the skateboard or inline skating feel for something that is more real and independent.