Well, there's going to be less of those. As construction industry is further incentivised to use more efficient methods and materials for their plumbing, driven by the ever-competitive housing market (that would likely see a crash in our lifetime, you know?) making the point moot. I think nobody is delusional that there's blue ocean in plumbing, or some hidden plumbing Renaissance of human labour. Do people even want to do manual plumbing in the first place?