Why didn't more SVB depositors take advantage of the SVB offering for sweeping cash funds into insured accounts?

https://prospect.org/economy/2023-03-13-silicon-valley-bank-...

> Importantly, SVB was part of the network of cash sweep banks; it had an offer on its website about it. But according to Adam Levitin, there were only $469 million in reciprocal deposits, which is where cash sweep would show up. In other words, almost nobody banking at SVB used them.