Question to PWM people - who makes the most risk adjusted cash amongst UHNWI?

Hi PWM friends, I am a sell side trader in the process of moving to the buy side (finally) and was thinking what I'll be doing with my life long term. I am moving to a MM hedge fund and if I manage to stay there for a decade I'll probably be fine but most people don't last that long. Plus, I've always wanted to have my own business. Hence my question is - you guys are chatting with HNWIs and UHNWIs often and have seen/spoken to many of them so probably have a decent sample size to know what makes them HNW/UHNW? Obviously I am asking about people who have built their wealth from scratch.

I assume it's mostly small/medium businesses and punting real estate but are there any particular sectors or general business strategies that you see being common amongst multiple people?

I've been thinking about saving up a few hundred K and then buying a small business to get my hands dirty before levering up and doing something on a larger scale. Have you seen anyone pull something like that off or do people mostly run businesses within an area of expertise they have acquired while working?