Health insurance is largely a benefit. It's largely cost-prohibitive to do otherwise, and I believe coverage can often be better from your employer than what's available on the open market.

You still pay for employer-provided coverage, but with your employer covering some portion of the cost. I think my out-of-pocket insurance is ~$300/mo as well, but most insurances will also come with a low-deductable plan that is sometimes, but not always, cheaper depending on how you use your insurance. Insurance only covers some part of a medical bill, and the lower price covers less. There's a ton of caveats on all of that though.

If you're unemployed, there are options. You can just go to the hospital without coverage, and apply for income-based relief once you have the bill. You can't apply before you go though, and you may or may not have your costs covered. Not paying at all of course impacts your credit, but like 90% (number pulled from my ass) of the US has medical debt, and I've had landlords for instance straight up tell me that ignore medical debt on the credit report.

There's some kinda public insurance available. I think it's largely for retired folks? Idk, I've never heard of anyone actually able to use it. You also keep your employers coverage for about a year after you leave, but you have to pay for it still.