You can't live without credit or loans, so they're a form of slavery. Or so writes a guy on an anon page, who then backtracks by saying it's just a metaphor.
But of course loans really are voluntary, which makes this perhaps the worst metaphor ever. You don't want to bear the burden of a home loan? Tens of millions of people live happily enough in rental housing. You don't want the burden of a car loan? Buy cheap used cars or live where you can take public transit.
I'm not saying life is necessarily more desirable under those conditions (that's subjective, and it is for some but not for others). I'm saying it's entirely possible. And normally, you don't need loans for much else (except education, maybe, but you can't blame capitalism for that, as this guy is doing).
But even more than that, the person granting you a loan is not enslaving you - they are taking a risk in order to help you achieve your goals. If anything, you come closer to enslaving the lender because you may fail to repay them, causing them an economic loss.
Do some people get themselves trapped in debt? Yes, but except for medical bills that is most often a matter of choice. And even with medical bills, it means someone was willing to care for you without demanding payment up front and in fact no guarantee of ever receiving payment.