It seems I mixed multiple issues together. I can't claim that I understand geopolitics enough to suggest that we should stop all military spending. I was mainly suggesting that for such a huge expenditure a clear case for it should be made to the public. The other issue I'm getting at is that there's no way the F35 should cost as much as it does. For instance if Musk for some reason was tasked with designing and building the next generation of aircraft I'm sure it could be done for at least an order of magnitude less than the F35. The money is mostly lining the pockets of sociopaths and massive intentionally inefficient bureaucracies.
If Musk wanted to bid on future US Military contracts I am sure he would be able to, but since he doesn't seem to be in the business of constructing fighters for the Air Force I think we can safely leave him out of this discussion.
The F-35 is a complex weapons and sensors platform, tasked, perhaps overtasked, for many different capabilities and mission-types. I think you can make a compelling argument that it may have been cheaper to divide those into separate proposals and take separate bids for more specialized fighters, but then you would have been stuck justifying each and every one of those to Congress rather than the F-35.
Not developing any sixth generation fighters when the competition is, was not an option though. I'm not happy, as a member of the public and US taxpayer with precisely how the F-35 turned out, nor am I happy that F-22 production was shut down by the Obama administration with the F-35 expected to fill its role instead.
