So, historically, NASA doesn't really make their launch vehicles, any more than the US Army makes their tanks. They buy from the lowest bidder who can meet the mission specs and then modify to purpose.

It's obviously a lot more complicated than that but the point is, "NASA's" cost overruns are contractor overruns that in large part are a symptom of a deliberately sabotaged system.

Tl;Dr the launch schedule should be controlled by NASA, with the rockets they own, purchased from the manufacturer that can meet their specs, not leased from an unreliable fascist.

If Elon can sell the best rockets, so be it, or Northrup, or Blue Origin, or whoever, but right now they're basically being forced into a subscription service for missions.