According to data provided by Musk, Space X's total revenue in 2025 is approximately $15 billion, of which the contract revenue provided by NASA is about $1 billion, accounting for about 7% of Space X's total revenue. This percentage is still very small.
In other words, if Trump really wants to completely prohibit NASA from cooperating with Space X, it would not have any impact on Space X.
However, Musk pointed out that the $1 billion paid by NASA is used for costs related to Space X providing astronauts and cargo to the International Space Station, launching research satellites, and some work related to returning to the Moon.
At present, there are no other commercial rocket companies in the U.S. that can replace Space X for these tasks, and even if they could, the costs that NASA would have to incur would likely be far greater than $1 billion.
It is not hard to see that what Musk actually wants to express is that Space X does not rely on NASA's contracts for development; on the contrary, NASA is currently heavily reliant on Space X's rockets to carry out various missions.
In other words, without Space X, NASA's space operations could become extremely difficult.
Perhaps it is precisely for this reason that even if Trump has issued many harsh words to Musk, it is unlikely that they would fall out in the face of absolute technological strength; maintaining close cooperation behind the scenes may be the best choice.