Comp has lifetime medical benefits for work-related injuries. If you're injured and can't work, who will pay your health insurance premiums (assuming you think you can rely on your health insurance to pay for these injuries for your lifetime.)
Comp includes benefits like worker retraining if an injury keeps the worker from returning to the same job as before. This can be very valuable.
Setting aside the money to handle claims instead of paying the insurance company to take this risk away from you is difficult - if only because it's hard to know how much to set aside.
Many businesses and individuals who hire you will require you to have this coverage, even though the state doesn't. I'd personally rather see you have coverage at low limits than not at all, and you'd be surprised how little higher limits can cost vs. lower limits.