This is broadly not true in most US cities. Skilled tradespeople who are insured, licensed, and bonded have major backlogs of work - especially electricians, but also plumbers, carpenters, etc.
You must not live in any major U.S. coastal city. Plumbers and other skilled tradespeople are in extremely high demand right now.
Its not just the trades, in my state, we have had an epidemic of retirements since 2008 for teachers, nurses, and police officers.
yet the programs that are required to get your licenses don't accept any more applicants per year than they did 15 years ago. The gatekeeping has to stop, or at least be increased to allow the market to actually meet demand. But the groups benefiting from that mismatch in demand have no reason to increase capacity.
I kinda doubt this. My mother wanted me to learn plumbing or to become an electrician because they were always in much more demand than supply and can effectively determine their own rates.
Most are self-employed. (UK).
I think the anti-college popularity ties directly to the incredible cost of it in the USA, not that its necessarily a bad thing.