Customers must first ask to borrow. Their collective behavior determines the multiplier.
Customers = individuals and private non-financial organizations.
Since the financial crisis, their collective behavior has caused the multiplier to drop significantly in the US:
https://fredblog.stlouisfed.org/2023/07/the-monetary-multipl...
https://fred.stlouisfed.org/graph/?g=13oHw
I'm very skeptical of simple, appealing narratives.