Meanwhile I think the hiring problem/solution is staring us right in the face.
What would the world be like if contract/freelance/part time/short term work were the default?
Isn't it perhaps weird that there is an assumption companies and employees should bind their fates together, and, if it doesn't work out, one or both parties is pretty screwed because of an investment of time and money which will likely result in a person being unemployed and/or a company paying a person far beyond when they are providing value.
This is like getting married after one date. Every time.
If employees were assumed to be exploring many things simultaneously, both sides would have plenty of chances to gather meaningful data about the employer/employee relationship, and if it is really a great fit, a long term employment arrangement could be worked out, with a contract that reflects mutual responsibilities revolving around this shift to an all-eggs-in-one-basket situation for the employee - and likely a corresponding move to much more critical functions being performed for the company.
I cynically suspect the current concept of full-time work evolved to suit employers, it allows them to manipulate and scare employees, especially when (for example) health insurance is at stake. Employers naturally have more data about salaries and so forth, in general most employers have many employees, while most employees only have one employer. That is inherently asymmetrical. Now that certain skill sets are harder to hire for, it is hurting everyone.
But the situation was never that great from the beginning, let's figure out a way to make it better for everyone.