They don’t need to prove their intelligence, but this entire line just throws off “but awkshully” vibes of someone who thinks too highly of themselves. Bolding mine.

Now I’m gonna say something that usually results in people telling me I’m arrogant and sincerely this isn’t arrogance it’s just fact: I’m extremely intelligent.

You know who brags about their intelligence enough to be told they are arrogant? Morons. Morons who think they are super smart do that.

If they left that one sentence out then the rest of their post as written would have made them look smart.