[ghaff]

Health insurance is a big one and a lot of people just aren't going to take a job that doesn't come with a good health insurance plan. Many companies also offer things like dental insurance, short term disability, and long term disability. Individuals (may) be able to obtain some of those things on their own but, as you say, the cost may be prohibitive.

You can at least get health insurance with pre-existing conditions now but it can be very expensive. You may not be able to get disability insurance.

Being a 1099 contractor is mostly not a good deal for someone who actually wants a stable long-term full-time job.