"from first spacewalk to moon landing in just four years is a reminder of just how quickly NASA was able to move, once upon a time"
True, but that was in a time when NASA was effectively on a war footing against the USSR. That NASA did what they did so quickly is testament to what you can achieve with huge resources, a reduced risk appetite and a national desire to beat a feared enemy. SpaceX have done great stuff with their huge resources, reduced risk appetite (for their uncrewed stuff that is) and maybe desire to beat a commercial enemy, whoever they think that is.