"Pitch" (ie the distance between keys, from center-to-center) must be the same at 3/4" for standard keyboards.
However, the perception of spacing can vary widely with the profile of the keys. For example, I am an IBM Model M/F user, and these keys are quite tall and tapered, so that the perception is that they are far apart.
Than is an illusion, however, the pitch is still 3/4" and it is simply the look and feel of the "plateaus" that you perceive, and which make you ignore the "valleys" in between. Lower (less tall) keys usually seem much closer together, but they aren't.
I suppose that I have big clumsy fingers, and typing on my phone, for example, is very difficult and frustrating for me, because the "keys" are tiny rectangles that are immediately adjacent to each other. I would be much happier if they were square and had zones of dead space around them, but that is my problem, I suppose.