https://en.wikipedia.org/wiki/Prisoner%27s_dilemma
> Two members of a criminal gang, A and B, are arrested and imprisoned. Each prisoner is in solitary confinement with no means of communication with their partner.
The guilty parties here could communicate with each other, and could cooperate, just like the banks did today by aiding First Republic. Instead, it appears that while they did communicate and cooperate, it was only towards the end of running on SVB. And as others have pointed out, even if the framing of it as a Prisoner's Dilemma is correct, it's not a single iteration variant: if the VC community could have come to some sort of an agreement, any party that refused to cooperate, or worse, that pledged to and then betrayed the others, would suffer a substantial loss of trust from other VCs and startups going forward.