That is very much the tragedy and one of the principal causes of the lack of skilled labour to build houses. Back in my teens I had a job as a painter and decorator and many of those around me had learned their skills, bricklaying, plastering, roofing, etc.etc. whilst working for the Council. Once Thatcher stopped Councils building council houses, those that were working for the council obviously went self-employed but no-one was then training people in these skills. So what we now have is that they have all either retired or approaching retirement with no-one to replace them as the developers aren't keen on training since their mindset is along the lines of 'why should we train someone up just for another company to then poach them?', so they all try to poach their builders from one another, except we are running out of them (https://www.placesforpeople.co.uk/pfp-thrive/insights-tools/the-uk-construction-skills-shortage/). This is why Burnham's plan to build 1.5 million council houses during this Parliament is simply 'pie in the sky', relying on 'the market' to deliver training simply hasn't happened and we simply don't have enough skilled workers to deliver on this. Of course we could rely on immigration but that opens a whole new can of worms. Of course the Government could subsidise these developers even more than they do now by having Government Training Boards to fill this skills shortage, but why should they if the developers themselves wont?