Although life is virtually certain to exist on millions of planets, on most it would be very simple, such as bacteria, which took 2 billion years to evolve into multicellular animals on Earth, owing to "Snowball Earth" as the triggering event, a phenomenon unlikely to be repeated often, and then it would have to be on a planet like ours, in the extremely unusual Earth / moon dyad, with a metalliferous type G or K star located in a relatively safe location in a spiral galaxy, well away from the hazards of its galactic centre.
It would also require an oxygen atmosphere to generate sufficient energy for animal life to be viable on the surface, (and an ozone layer to stop UVC rays) otherwise it would be more like plants, slime and slowly moving worms in the seas and rivers.
The unusual way that the Earth and moon formed, by the shallow angled collision of a Mars sized object with the proto-Earth is also vitally important, for multiple reasons.
It increased the rate of rotation of the Earth, and both iron cores were largely retained, creating the magnetoferrodynamics that power our strong magnetic field, protecting us from mass solar ejections of ionised plasma.
The mostly molten rock that was thrown out by that impact initially formed a ring around Earth, slowly accreting gravitationally until the moon formed.
The moon then played an important part, via the process of "atmospheric skimming". The composition of Venus' atmosphere is 96% CO2, 3.5% Nitrogen. The atmospheric pressure of Venus, which has no moon, is around 90 times greater than ours is now, but they would have been comparable in the early stages. Much of the Earth's carbon dioxide is now largely sequestered in carbonate rocks, like limestone (Venus has no plate tectonics, therefore no carbonate / silicate cycle). The blast, and heat generated by that collision enabled the mostly lighter molecules of the remaining atmosphere to attain altitudes sufficient to be blown away by the solar wind, and it has continued to a lesser extent (because the moon was much closer, then) for billions of years since, despite replenishment of volatiles in cometary bombardments.
The molecules in gases move at high speeds in "Brownian motion", with many collisions, some few of which, if the angles are right, propel them to higher altitudes, to a point where the moon's gravitational attraction enables even higher altitudes to be attained, to where they can be carried away by the solar wind. Photosynthesis by cyanobacteria generated oxygen from the carbon dioxide in the atmosphere, which was a "reducing" one, in chemical terms, not the oxidising one it is now, and it was that slowly increasing proportion that enabled the evolution of oxygen based respiration, with the much greater amounts of energy available for animal life.
The largest flying pterosaur, the four winged Quetzalcoatlus, weighed at least the same as a man, and possibly up to 200 kilograms / 440 lbs, or even 250 kgms. The atmosphere could not support anything larger. Imagine the size that a flying raptor could evolve to on a planet with an atmosphere 20 times denser than ours, or 50 times. Large birds of prey could have attacked adult proto-hominids, which were only around a metre in height.
When you consider that there have been several mass extinctions on this planet, and if it wasn't for the KT boundary event, the dinosaurs could still be the dominant animals, so it's easy to imagine that most planets would not have evolved in the same way that ours did, and that humanoid life forms are extremely rare.
Highly intelligent beings may well be considerably less than a hundred parsecs away, but either not technologically oriented, as were most of Earth's civilisations, such as the ancient Egyptians, Babylonians, Romans, Aztecs, Incas, Mayans, etc., (more likely) or they are only now evolving such a technologically based civilisation.
I estimate the probability of such a situation to be exceedingly low; considerably less than 1 in 100,000,000,000. It would surprise, and delight me if there were/are/will be more than several ones of at least our level of technology, in the Milky Way galaxy. The likelihood that, by the time we receive, and reply, (it may be assumed that some attempts will be made) they no longer exist, is high, and that we both continue to exist, and maintain high technology to receive their reply, is much higher, and increases in direct proportion to their distance from us.