Ok, given the size of the US budget and size of the US both population and land mass, the federal executive workforce is likely understaffed. The amount spent on the workforce is not excessive and is ~3% of the overall US budget.
These cuts to the workforce are performative at best, or designed to destroy the federal government at worst. Given it's Musk and Trump, I think it's the later. And they are doing this under the guise of budget concerns, which is clearly bullshit when they still have a $4.5T tax cut on the table.
So it's not whataboutism, it's was a quick way of highlighting how your post was incorrect.
For the record, I personally am completely against the tax cuts.