Yup, there is no difference at all between rich and poor in gambling, both have the same chance of winning and losing but maybe with different amounts, and that is the only difference between poor and rich gamblers
Another difference is their state of living before and after gambling. A rich person can walk away from losing in gambling and still be able to be okay afterwards but a poor person most likely won’t be able to afford anything else after losing in gambling.
If they do win though it will change the poor person’s life and maybe not so much change the rich person’s life.
The financial condition factor is the only thing that differentiates a person's situation after they are involved in gambling, as you said that rich people may still be fine even though they lose and that makes sense considering that rich people usually have many sources of income, the point is even though rich people lose they will most likely still be able to finance their living needs, but for poor people, yes in some cases they usually can't even afford to buy their daily food needs, but actually for this problem it also depends on how they approach gambling, because actually regardless of whether they are rich or poor, if for example they have an aggressive approach then the impact will definitely be very serious.