Well, if you don't treat your workers with respect you won't get loyalty. This isn't regulation's fault, nor is it the worker's fault. Back when corporations would keep people for their whole career (with suitable pay increases and promotions) and allow them to retire with a pension, then they would get people who would use their training and not take off afterwards.
Second order effects, indeed. More like third or fourth order effects.
In the days of pre-dot com boom, there was less disparity between the "what a person took home as wages" between the big tech of the time and the regular "keeping the computers running at some other company."
With the dot com boom and the (effectively) gambling on stocks that came with the highs, the ability to jump jobs and make way beyond what your former employer could afford to pay you started what we see now.
No matter how well you treat your employees, if there's a company out there that has a ceiling of 2x or 3x (or the gamble of what it could be with stocks at a startup) of what your revenue per employee is - there's no way to really keep someone and no reason to really invest in them either.
The "training and tie them down with clawbacks if they try to leave" was a way that companies would try to retain the lower skilled employees that they trained. That may be harder for them to do and thus harder to justify any investment now. It's awful, it's exploitive - but it was one of the few tools that they had remaining.
Treat them well and they won't leave only works if you're fairly near the top of the pay scale and they're not looking to settle down.
Couldn't they just pay them more? Offer them worthwhile promotions and raises. Someone won't jump to more pay if it wouldn't be that much of a pay increase.
I worked at a small logistics company for a bit. Looking it up, their revenue is $5.6M annually with 50 employees. Ignoring the operational costs, the revenue per employee is $112k. When factoring in operational costs, benefits and such, if the company is paying that much, it is losing money.
The city where it's based out of has a median household income $55,000 and a per capita income of $30,000. When I was working there on the wages that I got I was comfortably above what my neighbors were making - and way below what you'd make at a more profitable tech company.
Tech companies are easily making $500k to $2M revenue per employee. Microsoft has a profit per employee of $315k and a revenue per employee of $918k. If I was to go to work for Microsoft instead, there is no way that the small logistics company could pay me enough to be competitive with that offer and remain profitable.
This doesn't take into account stock or bonuses - just wages. Nationwide, most software developers are "just" comfortably paid at an amount far less than the big tech companies or startups trying to compete with big tech can offer.
For the median developer, a big tech job will always be able to out compete others on wages. And the big tech job is (up until recently) always hiring. Much of levels.fyi represents that 75th and above percentile compensation. But most developers are not working there when looked at on a national view rather than a west coast view.
I don't see how that is society's problem? If I can't afford the rent my landlord is charging there is no way to "tie them down with clawbacks" and force them to keep me. It's my responsibility to find the money to pay the going rate, or else they will find someone else who will. Likewise if a company won't pay the rate my skills can earn, I will find someone who will - don't push your responsibilities onto me. How they come up with the money is their problem.
Second order effects, indeed. More like third or fourth order effects.