Some extremely high net worth individuals place their money with "family offices" that pools money. Even some of them don't do well, just as a decent amount of hedge funds also don't do well that accept lower ones. Just because someone has a lot of money does not mean they are smart or intelligent or even if they are maybe they placed money based on a recommendation of someone else , willing to accept the risk since they have capital to spare, maybe put money in just to say they are involved, overconfident, lack of research or etc. I mean we could list tons of points and probably even some better ones, but the point is I think you're giving them too much credit. And of course everyone who has a lot of money doesn't mean they will automatically win.
Why do people start businesses? Most businesses especially on your first try often fail.
Also, responding to your other comment "trying to game professionals out of their money". This is not really true, unless you're trading really big size, trading is mostly just a game and a battle between yourself. People over complicate it and fall victim to all the information out there. Sure, it may be correct that trading is hard for retail, but there are people who make it. A lot of retail fail though because they believe the "common knowledge". Things like "algo's will get you" "big money has too much advantage".
You choose when to enter a position and you choose when to exit a position. You have more control over the market than you think. Of course I can't be certain because I don't know you or your exact situation but more than likely you are losing money because you are losing the battle against yourself, not professional traders or algo's. Being profitable rarely takes some master plan or incredible lengths with some perfect strategy. It's about being consistent, not having the pressure to make a certain amount each day and not trading so big that your emotions take over.
It's difficult to explain both of these things exactly how I wanted to and really long winded, but hopefully it's some what clear what I am trying to say.