Miniscule? You can make money a lot faster if you spot an edge in a gambling game compared to trading. In trading lets say you can make 5% a trade which could take a short time but mostly will take several days or even months. If you can exploit a 5% edge in a casino game, you can make that on every bet or few minutes! The edge is also not miniscule either, i know one roulette pro who said it could be anywhere up to 100% edge to the player depending on method used. The hard part is avoiding detection, because likely you are gonna get banned very quickly.
You can read about the medical professor who beat roulette here:
https://thehustle.co/professor-who-beat-roulette/
Heard of any such stories in the last 50 years?
What games have a "possible" 50% edge to the player... roulette too?
100% edge to the player? Win every time? Don't you think the house would notice that?