Yes, it is called education, common sense and incentives. Fractional reserve could be something like tether backed by USD

Seriously, good crypto should be limited and there is no way you are going to accept someone lending you bitcoin with a "bitcoin certificate". If you know your crypto bitcoin means bitcoin in your wallet address and with your own keys. There is no way you can borrow more than it exists if you have taken even the minimum required time to understand what you are doing.