As various Financial Twitter people have been arguing, why didn't the venture capitalists, who by definition have lots of capital, and often were banking with SVB and encouraging their invested companies to do so as well, buy out SVB?
Actually VC funds don't have much capital. If I agree to put $10MM into a $50MM fund as an LP, I don't send them $10MM. What I agree to do is that when they make an investment in Startup X, they can call me and ask for a fifth of that investment.
LPs invest in venture firms on the theory that the firms can pick good startups. I want the use of my money until they ask for it.
(This explanation ignores the annual management fee and the fact that some VCs have made a lot of money in the past).