why we don't see species closer to our own level?
what is our level? i look at it like if we're talking about the sense of smell, dogs have us beat hands down. if dogs had the ability to reason on things like a human they may wonder why other animal's sense of smell is so primative compared to theirs. or if we're talking about the ability to breathe underwater, tons of species have us beat.
humans happen to be the best adapted to rule this planet mostly because of the size of our brains compared to our body size. so we assume that we are the "best" and that other animals that have evolved differently somehow lagged along the way, or are dawdling in their evolutionary development towards human-like traits.
the assumption is that evolution should always point towards humanlike characteristics (like a big brain). this is not what evolutionary theory says. there is no concept of progress. every species on alive on earth at this time that is multiplying is perfectly evolved for this time. basically, we are the pinnacle of evolution...just like every other animal...just in different aspects (i.e. intelligence, sense of smell, sight, speed.).