Ending feels changed [SPOILERS]
The ending just doesn't seem to fit the whole movie.
Reynolds character could walk away because he was not chronic like Mendelsohns character. There is a big difference from someone who likes to gamble and someone who just keeps going and going like Gerry. Even when they were already up over a quarter million dollars, amazing from $100 start, his reaction was to "bet it all"
More money than he has ever came close to, literally life changing, and he wanted to risk it all in one toss. That is a degenerate gambler.
He was even acting bizarre as they were celebrating and eating steak and lobster. I believe the scene was to show how it's never as good as the chase itself to this type of person. I find it hard to believe the original ending planned was happy after that because the two scenes do not gel.
If I had to guess, originally they wanted to end with Gerry at a table when Curtis came down to check out, and he would be almost out of money again. Or something like that. If he was to pack up and go on to a new life, no need to sneak away.
The "we won big" ending where it seems everyone gets a fresh start doesn't fit. This wasn't a heist movie or two guys needing cash and getting lucky, it was about a degenerate gambler. One who gave up everything to his gambling. Everything.
Sure it was nice to see them do so well and get fresh starts, and Gerry crashing again to nothing after such a great amount of money would be depressing. But isn't that who he is?