I might beg to differ.

There is this saying, especially for senior or management roles, you'd rather be over-dressed than under-dressed, in interviews. The worst of worst, wearing a suit in a super casual, t-shirt, shorts, and flip flop environment, is you might be laughed at behind your back - this is a newbie here.

That being said, you show you respect them and take this opportunity seriously. Besides, it never hurts to look sharp (most people look sharper than usual, in a nice suit). After all, we are not talking about tuxedo here:)