The biggest problem with an apprenticeship model is that it creates a bottleneck to getting people into the trades. You need competent journeymen (and knowing the trade isn’t enough, they need to be able to teach) who ideally can take on more than one apprentice at a time. But no matter how much everyone “wants young people in the trades” and no matter how much of a “shortage of tradespeople” there is, the bigger shortage is apprentice positions. Every kid in the world could suddenly decide they want to be electricians and plumbers, and it would still take two generations to fill the ranks.
Note that I’m mostly focusing on trades that require state licensing. Laborers, carpenters, painters, plasterers, welders, etc. don’t suffer this problem as much, because there is no set amount of time for someone to be an apprentice. If you’re good and reliable you’re getting promoted fast. I’m not against licensing per se, but I am strongly against legislated work requirements for a job.
I know I could study for a week and pass the master electrician exam on Monday.