What’s a lenders advantage to providing a private loan?

[Account Closed]

Hypothetically, let's say a traditional real estate investor will get a loan from a local lender for 4%. But they have a someonr who could potentially offer them a loan for a lower %. Assuming that that person who was able to administer that loan is able to invest their money in anything else and provide a faster- ROI, why would they choose to provide their private loan to the investor?