People making most money _playing_ poker are really really good players that get invited to games with the wealthy people. This takes both poker skills, social skills (being entertaining) and potentially doing some occasional "fun" (incorrect) plays.

They are not the best poker players in the world. Best poker players have the misfortune of not being invited to "fun" millionaire games

If you have enough of an edge, the variance is really not that big. The only reason to have high-tech cheating when you already have a table full of fish - is if the people running the scheme are not very good at poker