Moving safely means moving slow, and that costs more - it's as simple as that. Plus it would also automatically disqualify like 80% of the workforce, due to the need for a proper formal education and certification, which would literally paralyze the industry.
And the current solution is not that different from what we have e.g. in civil engineering, the building codes for high-rise buildings are way more strict and complex than the regulations for a garden shed - in many places no permit is needed at all for it. And sometimes that means that that shad will fall in a catastrophic way, too.