Yeah, this is mind-boggling. The requested increase is roughly the size of the entire 2004 military budget. 2004, when we were fighting two separate ground wars.
There were close to 200k US troops on the ground in combat theaters in 2004. We're proposing to add a "2004 US military" to our military. The unnecessary wars we will start with this capacity[1] will cause havoc in unpredictable places.
We do it to keep manufacturing knowledge and ability in the country. I really cannot stress enough how many thousands of companies exist purely because of the defense budget. It's never going away because it employs so many people. That's why red or blue or independent no one ever cuts it. It's welfare that creates work so the whole ideological spectrum has something to like.
The big names you mention are the names that end up on the final product, but those products often have a couple thousand different (all American) suppliers feeding them. Virtually all of the money in the defense budget flows back into the economy. The sum total of those players profits last years amounts to 2% of the budget, and that's assuming it's all military.
A simple example are screws. You cannot make a living making screws in the US. It makes zero economic sense because it's impossible to compete with 2nd/3rd world countries (read:China). But the military (well contractors with a mandate) will buy your screws at a price that allows you to live a decent life and employ a team of people.
This way when shit hits the fan, the US will still have a supply of screws (pretty damn important), a supply of people who know how to make screws, and in the mean time those people get benefits and careers.
Now take this idea and repeat it for everything from paper cups to tank shells to folding chairs to wire sheathing (the military buys literally everything, always wants American made, and will happily pay a premium for it).
You're saying we need to retain manufacturing capability and expertise. I agree.
I'm saying we need to stop being bled dry by private weapons manufacturers on cost plus contracts who are rewarded, by definition, by making the system as expensive as possible.
If we were truly interested in having an effective military, we would bring production in-house and focus on standardized vehicles and weapons systems with standardized interchangeable parts on production lines that can be scaled up if necessary.