I think it’s premature to claim SpaceX will make it to Mars without deaths. They’ve only done two manned space flights to LEO at this point. While it does appear to be easier, cheaper, and safer to send people to space, sending people to Mars has never done before. It is going to be extremely dangerous.
I’m not sure NASA was financially irresponsible. They were doing things for the first time. Mistakes are going to be made, lessons were learned. That’s even true of SpaceX.
If your prediction that SpaceX gets people to mars with no deaths turns out to be true it will be because of NASA, not in spite of them.
All launches of Mercury era rockets had non-crewed test flights of the spacecraft. And they were on proven boosters. One benefit of using ICBMs is they start out autonomous.
Both launch vehicles for Gemini (Atlas and Titan) were again completely autonomous because they were ICBMs. They were tested and proven before astronauts flew them.
The first Saturn V launch was not crewed.
As I understand all US spacecraft were largely autonomous, especially in the boost phase.
SpaceX has refined that to automate docking but it’s not new.
Now, society is getting back to explore science more and more, but with a better, lasting attitude. See, for example, Space X. Likely, they'll send someone to Mars without deaths or even huge accidents that could only be justified by a lack of financial responsibility in NASA's early days.