It was in their best interest to cooperate to not run on their bank, and they failed to do so, which in turn brought down SVB, risks bringing down other regional banks in a domino-like fashion, and has already resulted in government bailouts that have made people outside of the SV bubble hate them even more than they already did.
Furthermore, the supposedly "evil" big banks, as I've repeatedly noted, have shown a comparatively greater ability to cooperate for the greater good of their industry and the wider economy, which is embarrassing given how these VCs posture.