So let’s set aside for just a moment the notion of single payer healthcare as an answer to this. Why hasn’t a point of competitiveness between insurance companies ever been that they keep your workforce healthier, more productive, and easier to retain than the competition?
The biggest cost to an employer is always their roster. The fewer sick days people need, the less burnout causes them to churn, and the healthier and happier people are overall, the lower the training, recruiting, and redundant staffing cost.
It feels natural to me that in an employer paid healthcare system like the one we have in the us, the employer should demand the highest quality coverage possible by that metric as long as it reduces staffing overheads.
By far the number one thing any employer I've worked for has done to reduce my number of sick days and visits to the doctor/pharmacy was remote work. Offices and gathering large numbers of people from over a wide area into a confined space by its nature is a vector for spreading infections. This is before even getting into issues like what a stressful commute does to the body and how it limits one's time that could, though not necessarily will, be used for healthier activities. But just the elimination of picking up colds, flus, and other infections from the office has had a significant impact on the number of sick days I've used. There also have been times when I was sick but not too sick to be productive. In the past I would have had to consider if using up a sick day and having no productivity was a good trade-off for not going into the office and possibly infecting others.
Maybe we should question this assumption that insurance companies intend to compete. It strikes me as very difficult to compare insurance companies. Some of them don’t even keep up to date information about the doctors that are in network (you have to call the doctor to ask).
Payers (insurance companies) do compete aggressively, but they mainly compete on issues relevant to benefits administrators who make the decisions at large employers about which health plans to offer to employees. Those administrators need to hold down costs for self-insured employers, and having larger provider networks means higher costs.
My guess is that despite the strong long term overall link, it's too difficult to draw a meaingful link between any particular executive decision on this and any particular outcome, causing a tragedy of the commons. I think it's a good guess because it's a powerful explanation for many other such questions about "Why don't they just ____?"
Patients on Medicare/Medicaid plans have similar or worse issues finding therapists who take that insurance, so I am mystified as to why anyone would think that a single-payer system would be any sort of solution.
While in principle I think you're probably correct that providing good mental health services to employees makes for a more productive workforce, it's tough to connect cause and effect in a mathematically rigorous way. We just don't have high-quality studies in this area to establish cost effectiveness. And many employees tend to leave anyway for other reasons.
We really ought to break the link between employment and health coverage. That part never made any sense.
People switch insurance fairly frequently, so if you could pay to improve someone's health, the insurance company is not all that likely to see much benefit.
Most employees at my current firm stay 2-3 years. That means that if you could "fix" a medical issue, it would often need to pay for itself in a year or two, which is unlikely.
Unfortunately, the economics to seem to favor what the insurance companies are often accused of doing: finding excuses to deny treatment.
Increasing employee pay would also boost morale, but it would be detrimental to retention - move money in their pocket means people have more options to quit outright or find a different job.
The same applies to good healthcare - employers WANT their employees to be utterly dependant on them and just barely scraping by so they're stuck.
Because those are long-term effects, and most companies have literally zero decision makers with any incentive to care about the long term. They all know the game. They're there to parasitize as much value as possible from the company or its common-stock holders in the short term and then fail upward and repeat the cycle. The long-term health of the company is completely irrelevant to everyone who matters.
The biggest cost to an employer is always their roster. The fewer sick days people need, the less burnout causes them to churn, and the healthier and happier people are overall, the lower the training, recruiting, and redundant staffing cost.
It feels natural to me that in an employer paid healthcare system like the one we have in the us, the employer should demand the highest quality coverage possible by that metric as long as it reduces staffing overheads.