While we don't have multiple examples of abiogenesis, we do have examples of particular traits being selected repeatedly and independently. Eyes,<br>Echolocation, and various other sensory apparatus have all arisen repeatedly. <br><br>Also, given what we know about life on earth; forward facing eyes making better predatory animals,  high protein diets building bigger brains, the benefit of opposable thumbs, etc.<br><br>It honestly wouldn't surprise me at all if the humanoid form wasn't just common in the in universe, but an eventuality.