Good question. It seems to me that American popular/media insults have been usually boring and vulgar for a long time. Verbal creativity in general is a bit lacking and would be unexpected in a short sudden insult. Here are some speculative hypotheses, but I really don’t know: I think perhaps calling Americans stupid also doesn’t hold as much weight due to the cultural . . . skepticism towards intelligence and learning. Possibly also for other expressions of disapproval, perhaps due to all the circular shaming, bad adult moralizing, and general disagreement on many values. And/or thinking ill of others is actually pretty common and expected – our politics have devolved to many people thinking “the other party” is nearly sub-human, and having to live with that. So maybe calling someone “deplorable” has little weight because we expect lots of people think we’re immoral and/or deplorable and/or fools, just by being not agreeing with them on politics. So we seem stuck on the vulgarities, branching out a bit recently with some newish combination-insults such as fucktard and fuckwit. I’m not sure exactly what you’re looking for, but there are a few, if not in common modern use: Scum[bag]. Filth. Knave. Coward. Heartless. Nincompoop. Greedbag. Fink. Slimeball. Disgusting. Jerk. Clod. Snot. Mouth-breather. Sociopath.