For most of my life, I have had the larger dog breeds. We lived out in the country, and there are always predators nearby. A Great Dane is much less likely to be carried off by a coyote or a hawk than a Chihuahua is ! Also, the larger the dog, the better of a protection as a guard dog they will usually be.
The kids and I went out horseback riding almost every day when the weather was nice; and the dogs always went along with us. If we had had small dogs rather than large ones, it would have been extremely hard for them to keep up with us as we rode back on the steep mountain trails for hours on end.
Now, I live in the city, and I am a whole lot older, my health is not good; so I am not out there doing all of those things that made a large dog almost a necessity.
I find it much easier to handle a tiny dog, and My Chipper is about 6 lbs, which is easy for me to pick up and carry, give him baths, and things like that.
He is an inside dog, so there are no issues with predators, and when he goes outside at nite to do his business, I am always standing right at the door to make sure that he is safe.
So, I think that one size is not better than the other, per se; but it is important to choose a dog that fits your lifestyle.