Not having credit means you’ll never get a mortgage, auto loan, etc.
So instead of blindly trusting your credit score as the measure of your ability to repay a loan, a human looks at your situation - income, other debts, etc, and makes a judgement call. It's more paperwork and slower, but it definitely exists.
Some banks will run a credit report from other agencies while opening too, but if you don't ask for or refuse any credit cards offered, you should have an empty report from them, once everything falls off.
But if you don't want to have a credit profile, then you can't use credit.