If the point is to clean beaches and that's it, I think my points hold. Sure, there are stairs on some beaches, but it's not really any significant percentage o

If the point is to clean beaches and that's it, I think my points hold. Sure, there are stairs on some beaches, but it's not really any significant percentage of the space to be cleaned up, thus not really worth optimising for IMHO. If the point is to _start_ with beaches and to then use the same platform to clean up all kinds of yet to be determined areas, a quadruped might indeed be one of the few viable options. Wheeled robots can climb stairs with the right platform, but I wouldn't argue they can traverse arbitrary terrain the way quadrupeds can. Personally, when designing robots, I have very clear tasks and constraints in mind, making conscious tradeoffs. But I'm a software developer, that's how we do things. It's perhaps not how professional roboticists do things.