Isn't insurance all I need?

No. Aboslutely not! First go read your policy. Not just the marketing materials or the fluff you get every quarter or year. Read your actual policy. Actively, carefully, and slowly read your policy. Look for specifically what is and is not covered. See how many words in there could be interpreted either way, see how many things sound like they're covered in one section, but excluded if scenario "B" occurs. I think you'll be amazed at what you thought was covered that is not covered. Maybe amazed isn't the right word, maybe terrified is a better word.

"Well, I'll just get an umbrella policy," you say. Nope. Wrong again: many umbrellas can be even more restrictive in what they do and don't cover. Repeat the active, careful, and slow policy reading exercise from your regular policy with your umbrella policy and prepare to be amazed/terrified. They also many times don't cover any losses that weren't at least partially covered by the primary insurance. If your primary insurance denies coverage and wins, your umbrella may do the same thing.

Insurance companies are in the business of selling you policies in exchange for premium payments, and then paying out the least amount of money (denying claims) at the latest date (stalling to earn more interest on your premiums). That's their business model. Oh, you have a six-figure slip-and-fall claim? You better believe the insurance company's legal team is looking for any reason to deny the claim. This is how they make their money.

If they do deny your claim, then guess what: you're fighting a legal battle on two fronts now: 1) against the Plaintiff, and 2) you'll be filing what's called a "first-party claims" lawsuit against your own insurer. And if you're operating without a proper entity structure in place, you're probably not sleeping much at night for the months to years it will take for the lawsuits to resolve.

Yes, you need insurance. It's a necessary evil. But, insurance alone is not the answer. You need your proper entity structure in the background protecting you where your insurance won't or can't protect you.