It seems like an easy solution to this is to have a 'trade academy' or a coalition of trade schools that allow / require you to do a rotation in each of the related trade specialties, i.e., if building / construction related, you spend a week / month / quarter learning about plumbing, electrical, framing, mechanical, landscape, etc. This would both promote understanding of related fields and give people an exposure to a variety of potential interests.
This is not unlike the required courses that predominate pre-major studies at a traditional university (in the U.S., at least)
I think it's still going to be hard to get 'middle class' parents to embrace this for their kids - and I am a 'middle class' parent.
If my kid wants to become an electrician I'd probably say "Why not major in EE?". A construction worker - why not major in Civil Engineering? If I felt my kid was fundamentally incapable of the level of effort required for those degrees, perhaps my opinion would change.
I'm on HN and I have an engineering degree, so I'm predisposed to think my kid could get one too. I'm not sure how I'd feel otherwise.
What you're describing is often done in trade high schools. Freshman will rotate through trades and pick one to continue on.
Once you need a career it doesn't really work like that though, often you're working years as an apprentice in a specified trade before you can even think about branching out on your own.
If you switch trades you're back at the bottom with apprenticeships all over again.
Someone like an English major can much easily change careers as long as they're somewhat adjacent (e.g., copywriting, research, journalism, etc) and generally starts off at a higher salary depending on their degree level. Until you hit masters level most degrees are broad generalized education.
Trades are specializations. If you're unsure about which trade you want to get into, you'd likely be better served with a business degree (which is another generalized area of study)... at least that can be applied across trades. Many tradespeople struggle with the business side of things despite being very practiced at their trade.
This is not unlike the required courses that predominate pre-major studies at a traditional university (in the U.S., at least)