I love robots. Check out this Unitree robot, the Unitree B-W, that is fitted with 4 wheels, and is able to climb stairs and speed around on its wheels.
It can walk, slide, turn and climb stairs. I think it has some way to go before it becomes commercial judging the way it climbs the stairs. Check it out.
Many people associate Unitree with Boston Dynamics because of the similarity of the robot. However, if you check around, there are many companies making similar robots.
BTW, I think Singapore is using the Unitree robot (kAI) for train inspection at the North East Line (NEL) depot in Sengkang.
Which one is your favorite?