Space X or TR3B

Let’s get this out of the way, I’m 100% believer. I want to hear any logical ideas of why would the government would spend money to use Space X to haul things into orbit instead of a giant TR3B (or same tech)? Also on the flip side, Elon obviously knows, it wouldn’t seem like he would use rocket tech if he knew there was antigravity or something like that.

I’m doing mental gymnastics here, but is it as simple as he’s 100% read into the program, and he’s simply a government vendor used to keep the 99.999 percent of everyone thinking this is as cutting edge tech as there is, meanwhile the very few are using antigravity for things like defense?

One thing is for sure, there is zero chance that he doesn’t know which is one of the only things that disappoints me from him. Makes me think it must be pretty bad for him to keep it to himself, or it’s just the vendor $. Who knows.