You have a point, overtime the dopamine effects gambling has on the Brain can make people addicted to it, even if they lose they still find themselves engaging in this disastrous habit. When it gets to this point they don't care about winning or losing anymore, they are just after satisfying the urge to gamble more. Another reason why people get addicted to Gambling especially casino games is from the lucky tries that they have had, a friend of mine made a thousand dollars on crash games and lost over two thousand dollars, he became addicted because he saw how easy it was to make money and fell into the trap.
It's not just the adrenaline, it's the pride too.
Who wants a losing endgame? If you are a man, you don't want that. It's also about pride and ego and losing means we cannot give up just yet. This is why many gamblers keep on depositing because they think that losing is the end game and they want their revenge against the online casino which could be impossible because as we lose, it doesn't mean we will win in our next match. There is a chance we will lose more.
I've been betting for a long time and I can say that only sports betting is the most time I can get back what I had lost. In casino games, it's difficult to do it. You can lose x5000 of your bet so let's say $50 at $0.01 but it doesn't mean you can get it back even after a long betting time.