Hindus, Buddhists, and Jains generally see intelligence as a continuum. Humans are at the top and are capable of escaping samsara but there is an idea of being able to fall down or up the continuum due to karma.

It's not a coincidence that these are the religions that have created the largest food cultures around eating vegetarian and vegan.

I can't speak for Buddhism but you got Hinduism wrong. Hinduism explicitly allows all Jivas to attain Moksha. There is an entire song on this called "Gajendra Moksha" where Gajendra (the Elephant) is caught by Makara (crocodile) and is rescued by Lord Vishnu, who grants Gajendra Moksha from Samsara. Another example would be that of Jatayu where Lord Rama gives him the status of his father (King Dasharatha) and performs his final rites, and then granting him Moksha. There are innumerable tales of animals getting Moksha in Hindu scriptures. Just provided 2 such instances.

Yes, but don't forget the law of karma and how most of the humans come from animal bodies in the past life. Everybody has a chance to burn their karma as an animal with no free-will and end up with a human-birth where you do have a free-will, and intelligence to use that free-will.

Right, but that concept is itself very compatible with darwinian evolution. Humans are the current pinnacle of evolution when it comes to intelligence, but that doesn't mean everything else is entirely unintelligent.