Welcome to the flip side of doing away with non-compete agreements. Why should a business invest so much money in training workers when they'll just get poached away by a competitor who is virtually guaranteed to be able to offer higher pay, not just for the value of the trained skill but because the competitor doesn't need to pay the overhead costs of training them? When new employees can leave their contracts at any time and for any reason, the expectations of employers necessarily shift away from training.
Now of course, reality is a little more nuanced. Training for long-time employees to keep them up-to-date makes more sense since they have so much domain experience internalized. A just law would need to allow for some exceptions to allow employees to break their non-competes in cases like toxic workplaces, and the law would need to set a maximum term for a non-compete to prevent workers from being exploited for low pay for their entire working lives.
But the notion that employers today should take "no-experience-needed" candidates off the street, give them 6+ months of full-day training with pay, and allow them to walk right out the door a week later to their competitor... is laughable on its face.