There are many gacha games on the market today that do post their odds and where player-validated data seems to support it. (Some jurisdictions like China and Japan require these kinds of disclosures.) But there are also a lot of markets that don’t require these kinds of disclosures and where there isn’t enough player data to draw a conclusion. So, in that case, how could you have confidence that they are not doing what you suggest? Even if they were, would it even be illegal? (If you never post what the odds are in the first place, is it fraud to keep changing the rules?)

This is why I’ve always been a bit surprised developers haven’t done more to get ahead of these kinds of issues with responsible disclosures and transparency, because it seems to be just inviting regulation. I honestly don’t think most F2P games pull the kinds of slimy tricks you’re accusing them of (most just use simple loot tables and RNG), but there’s nothing holding them accountable to say they can’t because everything is opaque.