1. Debit cards must use passwords. It's safer to use without signature.
2. Credit cards can be used without password, but only with signature (so-called international integration. Only signatures are recognized abroad), so be sure to check the signatures.
At present, most China users have passwords on their credit cards. For these people, the meaning of checking signatures is reduced.
So for users with passwords, it doesn't matter whether they check it or not. If you don't have a password, please be sure to check the signature, or everyone will be in trouble.