[sashahrzg]

SpaceX is a profit motivated company with large degrees of flexibility. They move fast and break ships. NASA is a research institution focused on scientific advancement and space research. They also are very rigid due to the way they receive funding. NASA cannot afford to move to a starship style system because the SLS contract was locked in.

[bottlepalm]

All that scientific advancement to end up 50 years later with a Moon vehicle not much more different than Apollo.