I'm not sure which of the two is more dangerous.
While Trump has the power of a government (and has a terrifying combination of narcissism and incompetence), I believe that if Musk had actually done the $2T cuts he was talking about, this would have ultimately killed around a million or so Americans — the number may seem surprising, I pick it because this scale cannot be reached without cuts to a significant subset of medicare, medicaid, social security, and the military.
Here's the graph from 2023, take your pick on how you'd cut $2T and then consider the implications in terms of lives: https://en.wikipedia.org/wiki/File:2023_US_Federal_Budget_In...
But again, you get that kind of scale disaster even if such things are done competently, and Musk/DOGE was doing all this stuff with unqualified people fresh from university and no experience is much worse… and unfortunately Trump is fine with unqualified people so long as they're sycophants or fawns.
tl;dr - 2T$ disaster cuts should be attributed to Trump, along with most of the responsibility for the aftermath.