I've found that rather than an actual focus on minimalism, the most successful people I've known tend to be very good at saying no to external demands on their time. Which is a form of shielding their time from being wasted by things that are not important to them. To run a business successfully as one example, you typically have to get good at that, or external demands on your time will persistently harm your ability to operate effectively (you end up like Lucy in the chocolate factory).

So rather than being minimalists, they avoid adding to their existing pile/s whenever possible. I can do this much and no more; they know their productive limits and seek to stay within those.