No, because VCs don't team up with each other to try to restrict competition. That's the definition of a cartel. In fact, they regularly compete with each other

No, because VCs don't team up with each other to try to restrict competition. That's the definition of a cartel. In fact, they regularly compete with each other by offering better deal terms (valuation, liquidation preference), or by bringing more to the table (counsel, networks, services).