“Death to America” doesn’t refer to killing every person in America, it refers to the death of a nation-state and the ideology it’s built upon.
Leftists use this term to advocate for the abolition of things like: fascist police death squads that kill disproportionately lower income and black/brown people indiscriminately and with impunity, the ending of American imperialism that immiserates the entire world while poisoning our planet, the end of neoliberal institutions (which we created) that enforce structural inequality across the entire world (like the IMF), ending nuclear holocaust and weapons proliferation, the evisceration of the bourgeois class that has plundered and profiteered off the natural resources we need to survive, etc; all of which are hallmarks of American structure.
Of course, too - to make an omelet, first you have to crack a few eggs.