So what is more efficient for this? : 4 years going in debt to get a well rounded education with a concentration in learning maybe 1.5 years of welding (in theory): or 2-3 years as an apprentice learning your specific trade and focusing on your one task (not in how many credits needed to graduate)?

We had this structure with apprenticeships. Companies were the ones to say "we need x people with Y mindset". And they can pay to foster those people and mindsets.

But they abandoned that because they didn't want to fit the bill for their own workforce. They instead put up with mediocre welders they kinda sorta train for 6 months and maybe the good ones stay. Great model for society.