At this point, what's the purpose of continuing with the Starliner program? Does it provide any capability that's not already proven with Dragon?
Whether that second provider should still be Boeing is less clear. But inertia and sunk cost make it easier to stick with them than to give the money to someone else.
Also, the ISS is will probably be retired in 8 years or less, so NASA could simply buy Dragon flights to cover them through that time.
It's not clear what the purpose of either vehicle will be once the ISS is retired, especially considering that Starship will very likely be flying, which completely changes the economics and practical possibilities of spaceflight.
Even in the context of the partially reusable Falcon 9, Vulcan makes very questionable sense, but in the context of the fully reusable Starship, Vulcan seems incredibly wasteful to continue flying.
And to counter the idea "the race is won, we don't need a second one", I will argue that we don't want this to end up like the Apollo program where we get there and then don't go back for 60 years.
- S.R. Hadden, Contact
I love the progress he's made, but it's unsafe to assume he's 100% aligned with U.S. interests.