It never really made sense to me for Artemis to be dependent on the success of StarShip development. If Artemis was a complete program, where it was launching its own lander with perhaps a second SLS launch and rendezvous in lunar orbit, then I would think it wise to not terminate the SLS development before StarShip succeeds with in-space refueling and the other firsts needed to provide a lander for the Orion capsule crew.
But, that is not the case. If StarShip doesn't succeed, Artemis is not going to be able to put boots on the Moon, at least not until Blue Origin catches up with the other two development projects. However, once StarShip is successful, SLS really is no longer a necessary component for the Artemis Program.
But, as I posted before, I am warry of the situation where Musk is involved in so many other activities, including very political activities, that might somehow hamper his ability, or even his intent, to keep funding the StarShip development process and or its focus on the Moon instead of just Mars.
"Failure is not an option" is just loose talk - failure is a definite possibility.
To succeed, we need a good engineering plan and the resolve to keep following it through various political changes. That is something that the Chinese seem to be able to accomplish. But, the U.S. has been very politically fickle about its space programs. So, even if there is a decision today to have NASA switch to a SuperHeavy + StarShip (and maybe + Orion) strategy, the party-dominated politics of our U.S. political system suggests that program plan could be scrapped within 4, or maybe even 2 years from now, because of the political affiliations of Musk.
It is very easy to be destructive - much harder to be constructive.