Closing down the US Social Security Department is the modern application of the comment, "Let them eat cake".
"Let them eat cake" is the traditional translation of the French phrase "Qu'ils mangent de la brioche", said to have been spoken in the 18th century by "a great princess" upon being told that the peasants had no bread. The French phrase mentions brioche, a bread enriched with butter and eggs, considered a luxury food. The quote is taken to reflect either the princess's frivolous disregard for the starving peasants or her poor understanding of their plight. Now it's often used to describe someone who is out of touch with the needs of others, as Trump and Musk obviously are.
Attributed to Marie-Antoinette, the phrase can actually be traced back to Jean-Jacques Rousseau's Confessions in 1765, 24 years prior to the French Revolution, and when Antoinette was nine years old and had never been to France. Rousseau does not name the "great princess", and he may have invented the anecdote altogether, as the Confessions is not considered entirely factual.