It's easier for them to let go, you are right

Because they know that they still have something left but the pain is there.
We can see the perfect example through Drake. He's rich and yet he's losing a lot of money from his bet. He can easier go back whenever he's been left by his losses.
But for sure there's a feeling like pain of losing it but it doesn't stay for so long.
Yes and I think it is a natural feeling to be felt by everyone who experiences something undesirable such as losing money, regardless of whether from the beginning you already know and understand the risks but still the feeling of discomfort will definitely be felt, but certainly do not let there be significant emotions and regrets in the situation, because that can be the initial trigger to push you to various impulsive actions.
On the other hand, for the problem of easy or difficult to let go of something that has been lost, I think it does not really depend on a person's financial situation, but depends on the responsibility that each person has, simply even though for example you are a person who has a middle financial level or maybe quite poor but if you have good responsibility in the sense of understanding that defeat is a natural part of the game then emotions, annoyance, and regret should not occur in you.