The Siamese is significantly different in size, shape, and attitude. So are most of the "oriental" breeds, but I bred and showed Measers for 15 years, so that's the one I know best.
And the British cat breeders of the 1880s-90s are the ones that 'fixed' the type (i.e. established a blood line that would breed true to type).
Anybody who has much to do with the Measers will tell you that they are different from other cats.
I also don’t get the idea that cats contributed nothing when humans had them join the tribe: they are ferocious hunters of small rodents, and any agrarian society needed that!
I also believe that there are breeders who are introducing some small wildcats into the gene pool. I have a cat who is supposedly part desert lynx. He’s pretty stupid and a bit jumpy. I also have enjoyed Blue Russians (not eating them silly but love the breed) which is much different IMHO than the typical domestic shorthair. Also love the Maine Coon Cat which I think must have some wild cat in it.
As you can tell by my screen name, my favorite is also the Siamese.
Siamese are vastly different than the rescues I have.
Rescues are extremely sweet, but as far as I am concerned, the Siamese are by far, much smarter.
There are two types of measers, the much more seen narrow style face and the original round apple style face measers. Truly they are one-of-kind.