One of the bigger problems is the failure of the construction industry as a whole. Compared to many other jobs, typical home builder trades (carpenter, roofer, brick layer) aren't competitive with white collar jobs.
-The hours through the summer are awful, with 16+ hour days being the norm. Then you hit the winter and are laid off and have to go on EI. If you're not good at budgeting, that swing can fuck up your finances.
-Work is physically demanding and often leaves you going home, eating, and sleeping to repeat the next day
-Pay is highly dependent on your company. Many only offer you an hourly rate while on site and working. Commuting (which can vary from a half hour to 2+hrs each way per day) is either on your own dime or at a discounted "travel" rate.
-Often people have a hard time starting an apprenticeship even if they're great workers with the education requirement done. The boss won't fill out the paperwork and actually teach the stuff they're supposed to, just using them as cheap/subsidized grunt labour.
-Bosses and the culture is awful. There are likely those who don't mind it, and there are companies which are better, but by and large my experience with various trades is highly misogynistic, dashes of racism, and lots or brash yelling instead of actual instruction. Communication is awful, and new workers are treated like shit to "earn their way in"/"do their time".
So it's hardly a surprise when there's less interest in trades/manual labour, especially when the pay is good, but not great.
I hate the "turn to the government"/why didn't anyone foresee this and subsidize the training that these articles often have. Sure, a portion of it is that. But a larger portion is the last 30 years of "Go to University to get a good job" that parents and schools have been pushing, plus a general unwillingness of the construction industry to improve their culture or increase wages to attract good workers/talent.