It's more that they are immune to irony, as long as the words they vomit out forward their hidden goals, they don't care what they say.

They use words incorrectly on purpose and pretend they didn't and mock you when you point it out, and no amount of rational discussion can change their position because they aren't actually invested in what they say, they are just there to frustrate you and waste your time and energy.

It's a game for them, and they revel in it. Easiest tactic is to just not engage. Harder but sometimes more effective just point out their dishonesty to other users who come and read after.

Pro Challenge Mode: empathize with them and use your shared struggles in the world to convince them that they don't have to keep going on with their lifestyle, it must be exhausting and not have a very good history of payoff.