The question of whether humans are the most intelligent life in the universe is a topic of great speculation and uncertainty. As of now, we don't have any definitive evidence of extraterrestrial intelligent life, so it is difficult to assign a precise probability to humans being the most intelligent species.
The sheer size of the universe, with its billions of galaxies, each containing billions of stars, suggests that the probability of other intelligent life forms existing is reasonably high. Many scientists and researchers believe that it is statistically unlikely for Earth to be the only planet in the vast expanse of the cosmos to harbor intelligent life.
However, the lack of concrete evidence or contact with extraterrestrial civilizations means we cannot make definitive conclusions about their existence or their level of intelligence. The search for extraterrestrial intelligence (SETI) continues through various methods, such as listening for radio signals or analyzing exoplanet data, but so far, no confirmed detection of intelligent extraterrestrial life has been made.
It is also important to consider factors such as the age of the universe, the formation of habitable planets, the development of intelligent life, and the potential technological advancements of other civilizations. Given the vastness of the cosmos and our limited knowledge, it is reasonable to say that the probability of humans being the most intelligent life in the universe is uncertain, and it remains an open question until we gain more information through scientific exploration and discovery.