This is relatively small pickles. Your employer paying a few hundred, maybe a thousand dollars on your behalf if you are old, per month. You can buy the same on healthcare.gov
They only things that I expect to change are total premium, deductible, out of pocket expense, copays, and network. Otherwise, the coverage itself is dictated by the same law.
I can see right now that the BCBS gold HSA premium from my employer (total, including employer portion) is the same as the BCBS gold HSA available on healthcare.gov.
I used a hospital for a new baby birth. Because my plan was on-market, the provider doing delievery didn't accept it (Despite it being on the in-network list). So I got to be stuck with a ~13k bill. Was super cool.
This was back ~8 years ago, so perhaps it's all been sorted.. but I have such a bitter taste in my mouth after having to pay this out of pocket, I won't touch on-market plans with a 100 foot pole.
I was paying <~$300/mo on that plan. I now pay over $700 on a directly-acquired plan. So that's problem one.
The bigger problem, IMHO, is that quitting means changing your insurance, which isn't just a financial change. It can also end up requiring you to change medical providers, which is no small deal!
This adds massive friction and stress to the act of quitting/changing jobs, a major source of leverage on the employer's side.
And that's to say nothing of the fact that it's effectively an overly burdensome tax on new entrepreneurs. It's a reinforcement of the concept, "you have to have money to make money".
JMHO on the topic; for reference, I'm a new entrepreneur very early in the process. I'm just lucky enough to be able to risk the attempt.