Just look at how poorly the couple of attempts at McD's to automate the cooking processes, they failed miserably... Even today there's a lot of manual work in automated factories.
"Plumbing" is therefore not a "shit job". It's well paid compared to most (Uber/Taxi/etc-)driving, cleaning, trash-collecting and many other jobs.
It all depends on the ratio "Ease-of-implementation" / "Cost of existing manpower" for each sector of job.
High effort and dangerous jobs usually pay well... low paying jobs are inherently manual, and/or likely to be automated away. In the end, some things don't automate well. There's a human aspect to a lot of things, and many of those won't be displaced soon. Of course, I do understand that many other jobs cannot fill the void that will be lost, especially with an ever expanding population.
Hell, if BostonDynamics can build RoboSoldiers, that can salto and run parcour, they sure as hell can build something, that can scrub my toilet. Currently I can't afford their "house-hold"-chores model, but in ten years Samsung will probably have a line-up of models between 1000€ and 10000€