The thing about SETI is that it is not really a search for intelligent life, it's a search for "intelligent life that broadcasts radio waves of a frequency and power that we can detect in a pattern and on a timescale similar enough to our own communications that we can recognize it".

Fermi's paradox basically boils down to: if intelligent life is at all common, it should be everywhere we look, and yet we don't see any. The traditional position is that therefore if we don't see intelligent life, it must be because it's too rare, or communication across interstellar distances is impossible. But the other possible answer is that intelligent life is everywhere, and we just don't understand or even recognize it as such.

The fact that we've been living with dolphins for millions of years and actively studying them for decades and have only just worked out a pretty basic fact -- they have names for each other -- despite the fact that they share most of their genes with us and live under the same environmental conditions exactly, suggests that we are probably really really bad at recognizing intelligent life that isn't exactly like our own.