The refi and leverage make a lot of sense if you are trying to scale grow and maximize your ROI. Especially if you are under 40yrs old. At some point when you hit your exit goal, you want to derisk. A portfolio of paid-off rentals has peace of mind like @Account Closed said which I totally agree with.
It all depends on the investor and how much risk you want to take. Some want to keep growing and maximize their returns and grow their net worth which makes them happy. Some want to hit their exit point and have zero worries in the world because everything is paid off. There is no right or wrong here.
From a lifestyle perspective, a person with $8m net worth has the same as a person with $30m. Maybe the $30m guy can fly PJ, have a bigger home, and has numerous supercars but they can pretty much do the same thing. It's a small difference. Is it worth the time, risk, and strain on your health to get there? There is a diminishing return at some point. In the end, do whatever will make you happy.