My cat has a function. He keeps rats, mice and other vermin out of my home.
Kept a rescue kitty for years. I had to put her down, and within a month there were vermin in my home. The dogs were utterly useless. They would literally watch a rat walk across the fireplace.
Got another rescue cat, no more vermin.
The cat has a job, the dog is the companion animal here
Okay, I didn’t think about the mouse and rodent duty some cats do, so some do have a job just like some dogs. Not all dogs are good watchdogs. Some, like you two said, are more companion animals. It works both ways and yes; there are smart and not so smart of both species. I have 4 dogs. One is really smart. Two are medium to very smart but stubborn and one is just not that bright at all but she’s still a good dog.
The only reason I never got a cat was because my dogs were never used to them so they just wanted to chase them and do what dogs do when they catch something. To my knowledge none has ever had that chance I’m happy to say. I like cats. I just like dogs more.