But are the schools artificially limiting their intake, or have their own resource shortages? If the former, what do they gain from doing so such that any individual school can't decide to it's better off accepting as many students as it can?
An electrician is doing hands on stuff in a lot of labs. That limits the student to teacher ratio that can be sustained. So, you'd need a lot more teachers who are already certified as electricians to come teach. Are you paying them enough to get them to come teach as opposed to work or manage? (LOL--teachers always get paid absolute dogshit).
After your first year of training, the expectation is that the apprentice is getting paid. So, you need to have some companies willing to cough up to pay more for the increased number of apprentices. Who is incentivized to do that?
Want more electricians? Bump the pay to $100K/year for a journeyman. You'll have lots of people wanting to be electricians.