The credit score system is a measure of the banks ability to make money off you, not your likelihood to pay it back.
Do you know why banks cover fraudulent charges on credit cards? Because then you don’t have standing to sue the banks when someone steals your identity. No loss = no standing.
Mine's right around 800 and I haven't paid a dime of interest on my credit cards in 20 years because the balance is paid in full every month. I've paid interest on my student loan.
You can't really separate paying back the loan and the banks making money from you. They go hand-in-hand if you reliably pay your bill on a loan.