SpaceX's, on the other hand, has been.
SpaceX may not be stellar, but it is definitely out of this world ;)
Elon Musk is just a guy, a key figure for SpaceX, but there are 10000+ other people, including Gwynne Shotwell who most people say is really in charge. In fact, I am not sure if Elon Musk does any actual work at SpaceX and Tesla now.
But let's pretend for a minute that you're right and all Elon Musk does is hire great people that then do all the work building the company for him and keep him at arms length doing nothing. The skill to hire like that alone still puts him in the top 0.01% of CEOs.
That alone overshadows everything NASA has done since the moon landing.
If you want to look long term, well, they're still stellar :) Considering everything they're achieving, and how they're so much better than everybody else in the field.
It's a failure only if you look at a rather small time range and criteria. Which I don't think was a surprise for anybody - Elon is famous for going for moon shots and failing, but still delivering better than anybody else.