As a heavily sarcastic and often irreverent person myself, I think sarcasm translates very poorly to online communication in public forums. The main problem is the complete lack of context where you don't know where a commenter is actually coming from, so you lack the ability to interpret them making a particular statement as a deliberate absurdity.

So sure, maybe talking to friends I would find myself using the word "fair" that way as a punchline to a joke. But they'd know I'm not looking to normalize the new dynamic, rather than highlighting its perversity.

Then specifically here, OP doubled down on the argument rather than repudiating it. So I don't think it's really correct to call it sarcasm.