Even if you do believe that these agencies are bloated with workers who are doing "unnecessary" work, which is possible, it seems very unprudent to make cuts so quickly. And who is qualified to make these decisions? Elon? Some Tesla or SpaceX engineer who wrote some code and put up a website? Come on. WTF do they know about how all these agencies operate and the downstream effects? You think they're taking the time to really think it through?
Now it's possible that prior to taking office, Trump had people with deep understanding of government operations go through everything, and really think things through, and prepare a list of jobs that could be cut without any impact, but if that is the case, it's never been said. Given who Trump has around him to lead these agencies (McMahon for Dept of Ed? An Oil and Gas Lobbyist for BLM? Really?) that doesn't seem likely.
Move fast and break things works fine for a start-up, and might even be fine for more cultural type stuff ("DEI"), but Dept of Energy?
It's like firing two-thirds of your sysadmins because "well, we haven't had any issues with our servers lately, and no breaches, so those people must not be needed".