You keep saying Musk and you are right Musk has no power, he just reports information to the President Trump who makes any call. So that part is irrelevant. The government can say we want to spend $1,000,000 on hammers but it doesn’t mean you have to spend $1,000,000 on one hammer. If the president finds you can buy a hammer for $10 then he can direct to 100,000 of them there instead. Also, if he finds government agencies are not performing on their obligations he can get rid of them. And lastly, a lot of changes are going to take effect until the next budget, which will be ratified by congress. Just because he says “we’re cancelling X” it doesn’t mean he’s stopping it now but once a new budget it passed.