Funny. I have a robot vacuum that I have to refill the water tank periodically and empty the dust bin. Even with your limited example, there's value in the automation. Thankfully they aren't restricted to just that. It's their first robot after all.
Also big time yes. Many folks would pay big money for a dumb robot that does just 1 or 2 tasks well - and even with that... how good is a Roomba really? It misses places, it gets stuck, and there's still 10M sold every year.
You want a robot that does the task well enough AND for which if it fails it's not a big deal if it's not too often.
For bigger robots that can break stuff it will be too annoying, but for Maurice, I don't think so.