There was a confluence of several factors which helped SpaceX to succeed, and not the least of these was the employee number one. For many years, Tom Mueller has been working in his free time on rather large liquid fuel amateur rockets, which he was building in his garage and which he was launching from some amateur rocketry facilities in the desert. In terms of regulation it was a relatively accessible hobby in the US. At the time Musk found him, he was working on the original "BFR" -- a very large liquid fuel amateur rocket. So the deal was to invest serious money into the project and scale the same no nonsense approach to a small orbital launch vehicle. They were in LA, the center of US aerospace manufacturing, so through Tom's professional connections and knowledge of who was who in the industry, they were able to source the necessary materials, components, and to find the key personnel for their company. Significantly, NASA has already spent probably a decade or more trying to get somebody to produce a cheap small launch vehicle. This did not directly affect SpaceX, but it did fund the R&D for example at Barber-Nichols, which enabled them to offer a turbopump for SpaceX engine at a much lower cost than it would have been possible otherwise.
At first, Musk and Co thought that they would be able to develop the rocket for a few million dollars. But even in the US regulatory environment it turned out that doing everything in compliance with regulations raised the costs to well over a hundred million dollars.
So, Tom's hobby + Musk's activism + industrial ecosystem in the area + NASA's prior support of component vendors + being at the right time to snag the International Space Station delivery contract were all important for SpaceX thriving where so many others have failed.
There are some (many?) European companies which are considered as least as much as a jobs program as anything else.
In 2018, Alain Charmeau (in)famously expressed frustration with SpaceX in an interview with Der Spiegel and rejected reusability with these words:
“Let us say we had ten guaranteed launches per year in Europe and we had a rocket which we can use ten times—we would build exactly one rocket per year,” he said. “That makes no sense. I cannot tell my teams: ‘Goodbye, see you next year!’”
https://arstechnica.com/science/2018/05/ariane-chief-seems-f...
from the original
https://www.spiegel.de/wissenschaft/technik/alain-charmeau-d...
A more recent example would be the Future Combat Air System (FCAS) project which was officially cancelled in June 2026, due to (?) industrial rivalry and leadership disputes, with a side order of politics.
It looks like he was an angel investor in Isar, and then co-founded a VC firm that continued to invest in Isar: https://alpinespace.vc/