So yes, if lucrative enough. But that's quite the qualifier, especially when you won't have a reliable income.
Well, that's partially correct. True for General Electric, but companies with 500-1,000 employees don't really have a pull. Remember that insurance is also bought by state, so only employers heavily concentrated in one state get those.
The biggie on the employer side is tax deductibility. US taxpayers generously subsidize the cost of employer-purchased health plans but not the cost of individual-purchased health plans.
As an individual you can tweak the situation in your favor (figure out if your doctor or dentist belongs to an HMO, join an HMO instead of PPO/EPO plan, buy a bronze plan when you're young and single, upgrade to gold or platinum when you're older or have kids), but the massive corporate subsidy still means that someone working for a corporation and receiving exact same benefit would be paying less.
Also, many big employers self insure and cut out the risk premiums. My current (large) employer offers an old school PPO with high copay but generous coverage including infertility, prosthetic and devices, etc for a total cost less than an Obamacare gold plan.