There is no comparison between car manufacturers ( highly skilled specialised industry) with limited cross-sectional industry based skill thus the requirement for training and the construction industries that use general labour, carpenters, electricians, plumbers, plasterers, cabinet markets painters, concertos, excavators, roofers, landscapers, fencers, glazers, etc... with skill that can be absorbed into other industries most tradies do there own work as well as work for employers in maintenance, renovations, etc...
Unless you are in the industry please don't generalise and quote stats as the end all
