To teach law you need an LLM and/or SJD. So there is a lot more $$$ and time than just a three year law degree.
To work in public policy, you don't need a JD. A BA/BS is fine. There are also Master's degrees in public policy that you can earn in 2 years for less time and money than a JD.
Having business clout is what helps in a business meeting. Yes, a JD is a prestigious degree, but it is, again, a lot of time and money to invest to believe that you can name-drop and have people take you seriously at a future business meeting. It is also foolish to think that having the degree and no practical experience will make you credible in a board room.
In real estate, you can become a real estate lawyer or become certified to sell property. You don't need a JD to be a realtor, broker or contractor, but you can pracice law within real estate.
People get a JD to become an attorney. You don't have to be one for your entire life and you can certainly change careers, but it is a three year investment of time and over $100K. You can get an MBA or a master's degree for less money and in less time if you want to be a college professor or learn business skills in a classroom. Think about it: $100+K. That is a lot of money. Three years of your life where you could be working and earning money, and having a life. That's 1095 days of your life, untold hours in the library, stress and being broke. Just so you can have a JD, the degree of an attorney, and then turn around to work and do something else. You can take $100K and 3 years of your life to travel around the world, get a master's, study under France's greatest pastry chef's, buy a house, start a business, etc. There's a lot you can do with three years and $100K. If you're going to invest it in a JD, do it because you plan to practice law, at least for a few years.