It’s a sin to gamble with other people’s funds. If it’s your not money, then you should completely avoid touching the money. I have seen many people take loans to gamble. They are forgetting that gambling is not at all sure money. There is risk involved and you need to understand how volatile the risk is. In such a situation if you risk other people’s money, then definitely you are risking your reputation against the other people whose money you borrowed. If you need serious money for gambling, then it’s better to do a serious job and invest only small portion of the salary in gambling to try your luck.
Do you really know many people who take out loans to gamble? In my entire life I have not known any such person, I have only heard stories about such people, so it seems to me that there are not so many such people who are ready to play for credit money. Regarding gambling, my opinion is that a highly paid job will bring you much more income than gambling, so it is better to spend time becoming an expert in some field and receive a stable profit, than to risk money and possibly lose it.
Gambling for fun, or betting for monetary return intentions are two very different things.
Define well what you want to do, and then proceed with financing your bankroll, and of course do not use this misinterpreted phrase: blah, blah "%" of your income, it is very bad advice, the problem starts there.
Finally, the best first bet is to pay a professional in the area of gambling addiction to identify if you are prone to addictions, depression, anxiety, etc. These types of people are the least indicated to tell them it phrase; "take a % of your monthly income to a Casino."