Relying on credit cards for emergencies can dig a deeper hole with interest. A small, separate savings goal is more doable than a full fantasy fund. Even twenty bucks a week adds up to a decent buffer over time. That way a surprise vet visit is a setback, not a financial crisis. It's about building a little cushion so the card is a last resort, not the only plan.
Is this really that serious though lol. I mean if you're living paycheck to paycheck you probably can't just drop twenty bucks into a book every week without noticing. That's still money you could be using on actual bills or food. And let's be real, most people would forget about that book and find it two years later when they're moving apartments. Or worse, someone borrows that book and your "emergency fund" is gone forever haha. I get the idea behind it but acting like this is some life changing hack is a stretch.