What if us humans are actually the most intelligent beings in the universe? I see plenty of theories that there is advanced beings out there but what if they exist and are just bigger dumbasses than us. That's a theory no one likes to suggest.
Miss Milky Way makes our beauty pageant contestants look like rocket scientists trained personally by Kim Jong Un.
The timescales are what make this hard to call. There's a fairly good chance that intelligent life nukes itself on a regular basis in one way or another. Star Wars had a great take on this with the "A long time ago in a galaxy far, far away" theme. The smartest beings ever to exist are more likely to be extinct now than hanging around waiting for us to find them. The smartest species on earth has evolved over a very short period of time cosmologically speaking, barely the blink of an eye. In the process we've seen dozens of species in the ballpark in terms of intelligence go extinct. That would be all the Hominini except for us.