Not the person you're replying to, but my take on it is that the checks and balances -- embodied by the legislative and judicial branches -- are only effective if a) they take action against the executive branch, and b) the executive branch respects them.
Congress is sitting on its hands and seems to be enjoying the view so far, for the most part. Republicans in Congress seem to think it's fine that Trump is usurping power vested in the legislative branch. Or at the very least they're afraid to speak up; every time they do, Trump threatens to primary them during the next election cycle. (I'm honestly not sure which is worse.) Democrats are "waiting for the right pitch to swing at" (paraphrasing Jeffries), as if doing nothing is some sort of strategy. And it's not like they can do anything anyway; certainly they have the power to get proposed legislation passed/not passed if Johnson loses a few GOP votes, but they can't get new legislation on the floor (y'know, like something that says "get DOGE out of the government's computer systems, right now") without the permission of GOP-controlled committees and Mike Johnson.
The courts are doing some things so far, but by their very nature, they're slower to act. But even if they tell Trump he can't do something, Trump doesn't actually have to listen. The executive branch is responsible for the enforcement of laws... and court orders. Let's say a court orders Musk to stop doing something, and he ignores it. Let's then say the court finds Musk in contempt, and orders him jailed. Who is going to arrest him? Not Trump's US Marshals Service, not Trump's FBI, etc.