Of course there’s no reason people on low incomes shouldn’t have the same access to protections and services. But there’s still the fact that £500 would be around a weeks wage for an average person in work - but a month’s for a person on that low an income. With a very high interest rate, It would be easier and faster to get into trouble.
If for some reason I only make the minimum payment on a card one month, it doesn’t really matter to me because in all likelihood, if I wanted to, I could pay the whole thing off next payday if I wanted.
If I’m on £500 a month and have a card maxed out with a £500 credit limit. It would be much much harder to pay off. Because out of my £125 a week a much higher proportion is going to be gone. As a person on a low income has the same gas, electricity, water, phone/broadband, TV license, etc bills as a person on an average or higher income living in the same sized space.