It's a useful model the same way a toy hotwheel is a model of a car. Yes they both have four wheels.
Notice the issue that SVB had was a huge influx of deposits and not enough loans.
Ultimately it's the capital that the banks have that limit how much they can lend, not reserves. Their capital requirements are the limit. Once capital falls below a certain percentage, the bank is in trouble.
Not completely wrong, after all.