The IRS usually goes after those without the means to defend themselves. Cheaper and faster. Audits are now performed at random too.
Insurance? Throw a rock and knock somebodies eye out etc. Hit a car with a rock and cause an accident. Hit a expensive paint job. Knock holes on somebodies vinyl siding( I once went under a tree with some kind of acorns and knocked hole in vinyl siding of a house). YOur equipment gets stolen and on and on
License? YOur city may require a license and the fines are big for those not having them. I was checked 3 times last year because the city did not send me a sticker to post on my windshield. They did this year. The licence is just a tax and required even if you only have one yard here