I'd argue that progress for progress' sake is a meaningless goal. Especially when "advance the state of the art" or "industrial grade components" aren't argued as concrete tangible value.

When it comes the latter part, defining that value is the essence of the debate. No matter how advanced the technology is, it's just a tool that serves a purpose. Once a business establishes a market dominance, what incentives remain to keep advancing that tech? What guarantees could anyone offer that SpaceX will stay on the "cutting edge" once that point is reached? And how will that impact NASA's ability to make operational choices regarding it's launch capabilities and it's larger mission to foster human exploration of space starting on Earth itself?

Finally, we're not discussing CRS-7 or Falcon 9. This is about SLS and it's Starship counterpart and which developed within their shared, particular timeline.