This is what markets like Polymarket boil down to. Normies can't win. Some will, of course, but that's just chance and there's no way if ensuring it's you.
It's really no different than a casino: if you ever find yourself with more money than you walked in with, cash out and leave.
Best strategy for most people though is to simply not participate and you'll break even.
Except, the thing is, a decent portion of the population enjoys throwing money away in casinos. If they feel a similar level of enjoyment/entertainment from this type of market, then it's no different and they're playing for a non-financial purpose that your calculus isn't pricing in. Maybe a stretch but theoretically, if they enjoy it enough, it can serve as a much cheaper alternative to a casino and thus could actually have a positive net return to one's personal finances even while losing.
And, I'm not even contemplating gambling addiction. There's a huge market of people that just go to Vegas once or twice a year and come home thousands of dollars poorer. But they don't need it, they may not gamble outside of Vegas, or nothing that would signal an addiction.
You say that like it's bad thing, but really it's great!
It gives us normies a way to see what the powerful are thinking.