Ah yes--so now we're up to narcissism, social pressure to wear a suit, or an aesthetic appreciation of suits in themselves. I will take you at your word that you wear suits purely to appreciate their beauty in and of themselves, and not in a narcissistic attempt to make yourself more beautiful by nature of being wrapped in such beautiful garments.
I didn't say it was the only reason I did it, that wasn't your question. The reality is few things we do can be ascribed to a single motive, more normally they're a mix of several things. But your question was name a reason which wasn't the two you gave of which this is one. There are others but given how much work it's been just to get you to gracelessly accept that there might be something here I really don't have the strength to talk about any others.
But the problem is still that your argument applies to lost of clothes, not just suits. Shirts are less practical than t-shirts. Buttons are fiddly and unnecessary, collars a pointless throw back to necktie and don't get me started on the practicality of cuffs. Most shoes are sub-optimal from a pure practicality point of view. Ironically many trainers aren't actually good for running because of the way they're balanced.
The problem is that you danced around my point rather than addressing it; perhaps if you had been more direct and to-the-point, you would have the strength to address it more convincingly.