You and I have different concepts of "solved case".
For you, if the fraudster returned the stolen goods (in this case, under pressure), then everything returns to the point where "nothing happened" and he is as innocent as a baby.
For me, nothing has changed at all and my main task is to warn other potential victims about the danger.
P.S. Think about the math: your approach encourages fraud - you can steal from everyone, and if the victim complains, you return the stolen goods (no negative consequences), if not, you keep them. There will always be a percentage of those who are lazy or don't believe in fairness, meaning the fraudster will inevitably statistically benefit.
Resolving cases is better than don't do that but I agree that if a case is resolved quickly and proactively by a casino after an accusation from user, it's better. Of course, the user already created an accusation and pressure by himself but it's better if a casino quickly look at it and resolve it if possible. If a casino only waits for bigger pressure comes from not only the user but also the community, it's worse for their reputation.
Even so, if they resolved the case, even late, even under bigger community pressure, it's still better than ignoring the case and moving on like nothing happened.
Of course, it will still be not perfect for their business and reputation, I totally agree with you on this point.