Maybe borrowing from someone you know like a friend or family member will not have any interest, but nowadays many people borrow money online and not just for gambling. In my environment, many people borrow money online and sometimes some of them are late in paying or cannot pay at all and it is clear that this type of loan has interest, so when they are late in paying or cannot pay, the interest can swell to be bigger and that will put extra pressure on them if they do not pay it off immediately and may make them stressed.
I myself have a principle not to borrow money if it is not because of an urgent situation.
Having the principle of not borrowing money is indeed a really good principle to adopt,, for some other person, it's a life style and so they don’t really care because they are used to it and now have it as a pattern and a life style so they don't actually even have reason to stop, and the aspect of borrowing to gamble literally is a very wasteful way of spending the money you borrowed, more like money that does belong to you.