Lots of places seem like they should have unlimited resources. I would have thought VW would be pretty high on that list - but they have their resources tied up. SpaceX / Tesla seem to be more free to use their resources in daring ways.
There's tons of places with effectively unlimited money. But very few places that have nearly unlimited resources. Some key resources are usually inversely correlated with money: decision-making latency and throughput, clear focus, and iteration speed. That's because money buys headcount, not good leadership.
Tesla can seemingly issue new shares and the public market just buy them all up at a huge valuation; I think that's what is meant by "unlimited resources".
That may be mixing up causality. One reason people love to invest is because they see what amazing things are possible. I personally would love to invest with SpaceX.
I don’t think you’re right about many others having unlimited resources. This situation is a novelty in the post-cold-war era. Admittedly in the Cold War military projects probably did have unlimited resources.
This made me chuckle. SLS is a bloated joke, survives due to political favoritism for job generation. SpaceX does everything at a radical discount by comparison.