This is a common misconception (I blame American politics). In _perfect competition_ this would hold true; however a _free_ market is not guaranteed to be competitive, much less close to _perfect_ competition.
It's not just competition, in credit card space, you basically have a duopoly with Visa and Mastercard.
If we were talking about bars, then yes, you have thousands of bars, and if legal, it wouldnt be hard to find a naked bar. But with two companies, you're far away from free-anything.
Absolutely that's why we have to have regulations. The larger companies get the more they tend toward being monopolies and warping the idea of free markets.
