> A lot of the advice we're seeing today about retraining in construction worker or plumber seems to assume that there's an unlimited demand for this labour which there simply is not.

I think that most advice like this is individual - not systemic. We all won't fit into the remaining fields when white collar work gets less demand, but someone who's just pivoting now still could. There's no systemic solution that will actually be implemented. The only advice left to give to people is to not be too late. There's only so many people that can be trained to do this range of work (has a physical component that is difficult to automate + can only be done here + has an education/certification moat) just based on spots in educational programs, and they'd probably be better off getting on that sooner than later if they think that their current job is going to be in the crosshairs soon.