Don't be delusional. You only can win
In poker, sports betting or stocks/crypto. You can't win with a system in Roulette.
To be exact you should say "You can't win in Roulette in the long run" because in a short run big wins can come up. And who gives you the garantee to win in poker, sports betting or crypto trading? It's the same - you can lose in all of these because they all need some luck to win.