In a technical sense you are mostly right in your proposition, but that is only if you treat animals by human standards which, obviously you cannot do because they're not humans.
It is true they cannot read or write. Neither of my cats will ever write Hamlet. I've always disagreed with the "Infinite number of monkeys" theorem. But they don't need to. They don't have art and therefore there is no need for them to express themselves in a literary way, or understand the literary works of others.
But that doesn't mean they're incapable of communicating. My cats let me know when they're hungry.
When we first had them, they would bring their kills home. I was forever shooing them away from the back door when they came home with a dead mouse in their maw. But why did they do this..? They did it because they think I'm a rotten hunter and need teaching how to obtain food. That is a form of communication.
I disagree that non-human species are incapable of construction. Rather, they construct what they need. Beavers construct dams. Birds construct nests. As for the advanced construction, I offer you The Honeycomb and the spider web. Apes have an opposable thumb and are therefore, in physical terms, as technically adept as humans. They have been known to make simple tools, such as stripping twigs of leaves to make rods to reach inside ant nests for food.
Animals do work. indeed, many sub-species of dogs have been bred specifically as working animals such as Border Collies for herding sheep. Dogs are trained for police work in sniffing out drugs or explosives. The blind are grateful for their guide dogs.
The human race has utilised animals for our own purposes for thousands of years and, because we are an advanced species, we have taken the role of master. But that doesn't mean animals are stupid, cannot learn or cannot be bred for specific roles.
It is true that their evolution has not been as rapid or adaptive as ours, but that is because they haven't had to.
A lion doesn't need to farm to eat. It is adapted to hunt for meat.
Humans - in an evolutionary sense - are not physically adapted to survive. We have no large teeth or claws. We are not powerfully strong and we can't run, jump or swim very quickly. By regular nature standards, in the wild we would be prey. We should have been hunted to extinction a very long time ago.
if, that is, it were not for our brain. It is our brain (and an opposable thumb) that has enabled us to elevate our species above the animal kingdom.
We shouldn't judge animals in a derogatory sense because they don't have our advantage. Rather, I feel, we should admire the way many animals have adapted themselves to live among us, provide whatever service they can for us, and thrive alongside us.
If they're passengers on the human journey, they're paying their way.
I agree with your assessment halfway. I have proof that animals can serve as a source of comfort for those in need. My cat Emil shares his body heat with my mother when she is hurt or in a bad state of mind. This helps her recovery very well and at present, I couldn't have a better companion for my mother. In this respect, yes, animals are definetely of value.
However, Emil's disadvantaged in that he can't be a more integral part of human life. He has been unable to support me in times of difficulty and I've had to bear the load of taking care of my mother without a fellow bipedal being at my side to give me aid of any kind. I wish he had and maybe my life would've turned out differently - I endured some very difficult struggles and Emil was unable to do anything about it. If he'd been human, he would have. I've been forever marked by that.
Also, Emil never got to meet other people and introduce them to me or my mother, another disability he's got as an animal. He's admired and he should be, but that doesn't change the fact he can never integrate into human society as he could have had he been born a human. As loving as pets can be in an urban environment, they can't participate as much as they should.