Leet me explain something that is education 101 with humans.
Humans are by nature liars, frauds, and corrupt. When you say that Trump and Musk are finding fraud and waste, it goes without saying because if you look closely, you can find fraud and waste in each and every administration. As such, the probabilities favor the fraud and waste from the last administration is going to be replaced (not thrown out) by Trump's and Musk's fraud and waste.
What is worse, is given that Musk and Trump (especially the latter) have shown huge amount of waste and fraud in the past, chances are that the fraud and waste "to come" will be larger and more hidden, given that both (especially Trump) are proven liars.
Last but not least and already being proven, is that what they say is not all that true and real. That they have lied about how much fraud and waste they have found,
Both Trump and Musk have shown incompetence (Musk with X and Trump on numerous occasions with many failed companies) and as such, their actions are going to be by nature destructive and not constructive.
End of story