One common theme is that companies used to treat good employees as assets. Now they treat all employees as liabilities.

What changed? A lot. The underlying theme across all companies, to both employees and customers, has been "see how much abuse they'll take before they leave", which sadly has had marvelous results because the answer is... a lot. Notice that at least half of the largest companies by market cap have no actual support at all.

Add in that tuition has exploded, it became cheaper and quicker just to import people than to train them.