In theory a new entrant could achieve similar feats with lesser money . For example rocket lab is doing pretty well for their size with some real innovation based out of New Zealand! Extremely likely part of their staff would come from spacex ULA, NASA etc . Similarly spacex would have leveraged from ULA , NASA as well .
NASA also does help them in some areas as part of this program and others and also the money they (and others) have spent during the last 15 years especially without validation. Very few customers would invest in 10 year product development journey they way NASA has with CCS.
That would not possible without NASA’s own budgets being so large to support kind of projects like the shuttles and ISS in the first place . Only then the couple of billion they spent will look small enough to take that risk.
Rocket Lab isn't out of New Zealand, that's a popular underdog myth at this point. They're an American company, funded overwhelmingly by big US venture capital, that built their current technology primarily in the US.
The initial low scale efforts for Rocket Lab originated out of New Zealand, with sounding rockets. They moved to the US because they could go no further with the limited native aerospace and funding capabilities of New Zealand.
Their name is now Rocket Lab USA. Their headquarters has been in the US for most of their existence and progress.
And most of their efforts and expansion are now also focused in the US:
https://www.rocketlabusa.com/news/updates/rocket-lab-expands...
New Zealand didn't have the native aerospace engineering capabilities to build what Rocket Lab has. Most of the advanced engineering was done in California, leaning on the massive aerospace resources of the state.
Australia has only had its own Space Agency since mid-2018, and its budget is minuscule (less than 10 million AUD a year.) I think Australia should aim to spend a similar percentage of GDP on civilian (non-military/non-intelligence) government space spending as the US does. Given the US economy is about 13-14 times bigger than Australia's, this would suggest ASA's annual budget ought to be around 1/13th or 1/14th of NASA's annual budget, which would be at least 100 times bigger than ASA's budget is currently. It really is an investment in the future of the country, ensuring that it doesn't get left behind.