What are some harsh sounding invectives that are not vulgar?

I have noticed that in english, invectives are polite sounding/vulgar or prejudiced. Why is that? So hard to express your feelings about something without sounding like a vulgar vagabond. In other languages there are many words that harsh sounding and confronting. Something like “You are deplorable” doesn’t sound confronting at all.

Words like ‘idiot’ or ‘fool’ are not harsh sounding at all. I am looking for precise words too.

Insipid, diatribe, morally bankrupt, vagabond, rancorous are some examples of words that are confronting or precise.
“Thou rancorous long-tongued hag” is a funny shakespeare phrase to use as insult.