When a bank makes a loan, they create a loan and a deposit from nothing, they don't need deposits to create loans.

Banks are subject to capital requirements, and are concerned about profitability and loan losses, so they don't make an unlimited number of loans.

This might seem like semantics but someone who believes reserve requirements and deposits are the limits on lending would find it tough to explain why banks aren't lending huge amounts after the reserve requirement in the US was cut to zero.