Given the only real mass market "robots" that are popular currently are stuff like hoovers or lawnmowers I can't possible see how trades such as plumbing are at risk any time in the next 20+ years. This is from the perspective of UK / European housing where a huge amount of houses are over 50 years old and so each set up is completely different. Different heating systems, thermostats, piping, connectors. Maybe in a new build property where every house is essentially the same there might be some chance of automation, but in traditional housing I can't see how that would work until robots are essentially "humans".
It's very obvious that humanoid robots will be quite capable and mass-produced in well under 20 years. Just do some searching on YouTube for humanoid robot and combine that with the progress in AI. The robots are improving quickly. I would be surprised if we didn't have something quite useful for the price of a car in less than 10 or maybe even 5 years. Just look at the state of the art and project improvements every year.
