This part never makes sense to me. I've had friends stay in jobs to keep getting healthcare treatment - it's not great.

It's a complete relic from the WWII era.

It's a relic from the days when Americans only wanted "upstanding citizens" to get subsidized healthcare.

It actually came about due to labor shortages during WWII. So many people were drafted into the military or voluntarily joining that employers were having trouble finding enough workers.

To prevent this from leading to rampant inflation the US passed laws that regulated wages and prices, such as the Emergency Price Control Act of 1942 and the Stabilization Act of 1942.

Insurance and pension benefits were not counted as wages, and so employers that could no longer legally raise wages to get people people to come work for them instead started offering health coverage.

Americans, who before this had largely been on their own when it came to healthcare, liked this, and so even after the wage controls ended unions bargained to keep those benefits and over the next decade or two expand them to include vision and dental benefits.

By the early '60s it was clear that there was a serious problem inherent in this. Employer sponsored health insurance had become that basis for nearly the entire American healthcare system. People who then left that system such as when they retired often found they could not afford to buy their own insurance. And so Medicare and Medicaid were created to try to handle people who could not get employer provided health insurance.

We almost got major healthcare reform in the early '70s. Senator Kennedy proposed a single-payer system that would be available to every American. President Nixon proposed a system that pretty close to the ACA (aka Obamacare). Then Watergate happened and pushed healthcare reform to the back burner were it sat for around 40 years.

Racism and classism is an equally convincing explanation.

There’s Medicaid for these situations

my healthcare was actually better when i was unemployed than it is with my current company

Right? I was on Medicaid for about half a year because of weird bureaucratic reasons.

It was the best health care plan I've ever had in the US. No deductible, copays were literally $1 or $2. I had access to the entire Kaiser system for routine stuff. You literally can't buy an insurance plan as good as the medicaid that I got.

Of course, now I live in Canada. That's even better.

Mind you, this was in Colorado, which took a vey progressive stance on Obamacare. I'm sure that there are places where medicaid is close to useless.

It's not. You can buy (and deduct) it on healthcare.gov. Ask any self employed person.

You're also paying it out of your salary with employer. There's no such thing as "employer match."

There is such a thing as employee and corporate bargaining power. Many SV companies adopt gold plated health insurance policies on top of competitive wages. I suspect hat this extra bit of health insurance helps prevent the perception the employer is overbidding on labor.

Similarly large corporations can negotiate to get better insurance rates, and larger insurance providers negotiate to get more cost effective care.

(One of) the problems with the health system in the US is that once you exit this negotiation scheme, prices go insane. A hospital might list a procedure for 2 million dollars only to take home 50k from the insurance provider. I don't believe anyone has a handle on what the true cost of any health procedure is.