They are two completely different things. Even in the event that Bitcoin becomes a medium of exchange (currency) in the future, because today it is succeeding more as a store of value, it is normal that it coexists with other currencies. Then, if banks give loans, they will not give bitcoin loans, they will give them in other currencies, either fiat or shitcoins, and in any case they will ask you to leave Bitcoin as collateral.
Lending in the fiat system is a way of creating money out of thin air, and that cannot be done with bitcoin.
Bitcoin has been the best financial asset to protect you from inflation and will continue to be so because of its intrinsic properties, especially its limited nature, as noted above.