I formerly published three books as just me without a company/imprint. That's because I was doing my taxes for years as a sole proprietor without forming a LLC. More recently, I did form a LLC for my therapy business. My books that I intend to publish this year are related to mental health/self-help. So, I made a new KDP account with my LLC and will use my company name as the imprint name for all upcoming books. This makes taxes more complicated though potentially lower. Given how much cost and hassle are involved in making a formal LLC, I don't recommend that someone do that unless they are sure that their annual gross revenue is above something like US$80k. Below that amount, you add expense and headache without a lot of benefits.