I see you’ve chosen confidence over accuracy again

This is honestly a great way of calling someone stupid, but you do realise that it can be very offensive to people with narcissistic personality disorder, right?

Joke aside, what is really stupid about this is the idea of “insulting someone without hurting there feelings”, or as you wrote

insulting someone’s actions or reasoning can sometimes carry ableist implications if we’re not careful.

When honestly insulting someone, there is typically an intent to be hurtful, the idea that you should be careful to “not use language that can offend X group” when doing so, kind of overlooks the whole situation of “insulting” going on