I take a Kurzwielian view. There is probably a significant transition in the physical bodies of an intelligent lifeform past a certain point of evolution. and a dramatic increase in cognitive ability.

Fermi's Paradox makes more sense when you theorize that ET transforms its biology into a computational substrate prior to gaining the ability to travel between stars, as will likely happen with us. When it does this it turns into something we won't even recognize, something likely a million times smaller than us due to miniaturization, and a trillion times smarter. Even if they are around they probably don't have the patience to interact with us, dumb as we are and with minds that travel 10^5 or so slower.