Why do I still want to have POS systems and have to have a "credit card". So instead of the piece of plastic, I have to carry my phone and a piece of plastic?

Why do I still want to have POS systems and have to have a "credit card". So instead of the piece of plastic, I have to carry my phone and a piece of plastic? I'd much prefer to see a comprehensive shift away from the credit card companies and PoS systems entirely.