Simlab is just another useless hurdle to go through. Real preps are rarely ideal, but follow the same principles, you'll probably never cast your own post, make your own diagnostic waxups, etc... unless you really love that stuff. I hope we're on the same page when we talk about real-world dentistry: pretty much being a profitable dentist. Only thing I can think of would be to work on extracted teeth, learn the anatomy for root canals. Take an occlusal xray of #3/14. Learn to read the radiograph and pulpal floor and you'll get MB2 most of the time. Also learn to read/know when there's a 3rd root on #5/12. With a lot of other dentists, I see that they either rush and do a terrible job w/ endo because they don't care, or they take forever because they don't know what they are looking for. If your business model entails doing the former, just make sure you don't do that to a specific demographic that likes to sue and a state that has tort reform (limits on damages). The latter is more preventable by learning how to access and read the pulpal floor chamber. Getting down to the apex is the easiest part. Most people fall into the trap of doing terrible root canals because they work for corporate where there are little consequences to doing bad root canals. When you bring that to your own practice, this can bring a lot of headache to you and explaining why you have to pull the tooth out. Most common excuse that the patient reports their dentist said is that the "root canal didn't take hold or your body is rejected the root canal." Professionally, nothing will probably happen unless they aspirate a file or you have a severe bleach accident. However, lawyers are expensive.
Anyway, case in point - practice molar endo. It's the gateway to profitability. Also, learn to prep CEREC crowns in 5 mins or less. Doesn't always happen, but you want to be fast. Electric handpieces + two striper burs are my go to + diode laser (avoid cord + hemostasis). Stand up when you're doing your work - you'll notice you can see more and go faster as a result.
You should be reading and studying business models. There's more than one way to develop your business model. Are you a process-oriented individual or goal-oriented individual? What I mean by that is will your end goals determine how you want to practice and what you want to do? Or, do you want to practice a certain way with less regard to the end results. Once you answer that question, that will determine the type of practices you can have. If you were more interested in a way of practicing, that may not necessarily coincide with your end goals. Vice-versa, if you have more extreme goals (massive wealth, superearly retirement, etc...), then you are limited to your practice types, as certain practice types are more successful than others. I think once you answer that basic question, you can educate yourself more on the business aspect of dentistry. I'm hard pressed to recommend any specific book that will tell you everything, and many of the literature out there is horrendously biased. I tend to read books about business in general, then think about ways to apply them into your current/future practice.
Dentistry is not unique and we are in a unique position to market ourselves as a service and/or product. There are advantages and disadvantages to both, but also depends on the market you're in. In a more highly competitive market, it's better to present yourself as a service. You can charge more and justify charging more for "quality". The downside is the expectations are higher. The alternative is to present what you do as product-oriented service. In a less competitive market, this would be a preferred way of marketing your practice as products tend to have lower expectations, can be delivered faster w/o the patient feeling that they didn't "get their money's worth". Also, charging as a comparable product to higher end items such as TV's/cars makes it look less expensive.
This barely scratches the start/extent of how you should start looking at dentistry as a business, but these are the logical steps that go into my mind when I first started. There's a LOT more. Other practice owners may not agree with me on these sentiments, but these are my perspectives on how to be a successful dentist. I hope that this brief discussion will help you in your journey of being a profitable dentist and frame the mindset that you should be in dental school. Just pass and focus on the business part. If you ever become supersuccessful, remember me and throw some money my way if I'm still alive 😀