I'm not surprised things like roombas aren't all that widely used. Vaccuuming isn't particularly dangerous work, and roombas aren't all that cheap. Things like, servicing nuclear meltdown sites and other hazardous locations, however, is a great use of robots that does seem to be fairly widely used. Also, the use of drones. Though, I suppose it depends whether you consider remote controlled machines in the same space as autonomous machines, because drones and things like Vicarious Surgical's "robot" might not be fair to compare to fully autonomous systems that act purely algorithmically.

Maybe at some point we'll look to robots to do things that aren't so difficult for humans to do, in the same way we use dishwashers now, but I think most things we recognize as robots just don't have the best cost:benefit ratio, especially when we consider the inertia of having a routine that already has us doing things manually.