Yeah, it's weird! But, trust me, it's less weird with context. This is motion-capture actor Terry Notary, who has starred in the new Planet of the Apes movies, as well as Kong: Skull Island and a number of Avengers films (and who, full disclosure, I have interviewed in the past and who is very nice and knowledgeable about all kinds of different styles of acting). That's a man playing a dog! He deserves some respect, not least because I am willing to bet he is dog-acting way better than any of us could do, and probably better than even a lot of real dogs.
The animation also looks quite good, when you get past the fact that nearly every landscape is altered or painted-over or completely fabricated in some way. I am here to say: Get over it! Get over yourselves! Look at the flowers, the trees, the way the sled dogs sometimes have little expressions on their faces! It's kind of fun to see! We've come a long way from counting the couple thousand hairs on Sully Sullenberger's back.
I've seen a few people saying that if Disney had just gone back to their roots and done a traditionally animated 2-D cartoon adaptation of this story, with this same level of care and attention to detail given the tech they have now, it would look incredible, and I don't disagree with that. It's also an interesting thought experiment to keep you up late at night. This version of The Call of the Wild is a movie starring a human playing a dog that's slowly un-domesticating itself, betrayed by the human society that created it and re-learning all the instinctual behaviors bred out of it from its ancestral wolf days. As Buck becomes wilder, Notary, playing him, stops performing the typical dog behaviors of before: he stops holding eye contact with humans, runs further and further into the woods with his wolf pals, and accepts less and less attention from people.
The Call of the Wild seemingly exists on the cusp of some unknown new way of filmmaking: the closer we get to replicating the natural world, the further we are from actually incorporating it into our entertainment, opting for pixels instead of flesh and blood. It's the kind of sobering artistic conundrum you can't help but admire.