Except that the reality of the situation is very
different now than it was 10 or 15 years ago, because of legislation pushed through 5 or so years ago to stop predatory lending on young adults.
And while you don't need a credit card, you will need a credit history. And having huge obstacles in the way of establishing one before you are 23 or 24, and realistically need one already, is really problematic.
If you can't save up $500 for a secured card, how can you pay off $500 on a card? Perhaps it's better to *not* have a credit card if your finances are that tight.
You shouldn't be going anywhere near your limit on your card anyway, since it's bad for your credit history if you do. And it's far, far easier to pay off $650 over time than it is to put $500 down.
Plus, the point isn't to have a credit card for the sake of having a credit card, the point is to have a credit card so that you can establish a credit history. When I got my first independent card, I used it for groceries and gas. That was pretty much it. But those small transactions, and small payments, on a $1k limit are easily the bulk of what has contributed to my credit score today. But I could only get that card because my parents were able to support me in establishing a credit history. There was realistically never a point in the past 5 years where saving $500 to put down on a secure line of credit was possible. But not having a credit history now would be a huge obstacle for me.
The other side of things is that there's literally no education, or was not in my school, concerning credit, credit scores, etc. By the time I knew how important having a credit history was, I was already past the point where I should have started establishing one.