@alowhum Zigbee being "a standard" is not an advantage at all. As you put it, it is indeed not true at all. Using "a standard" in the meaning of "a formal definition of one of the piece of your puzzle" is only an advantage when you want to potentially replace that piece by a piece produced by another manufacturer and still get that talking to the rest of the puzzle.
You should also consider that there are two kind of standards : "committee" standards, where experts provide a formal document and people pay to adopt that way of doing things, and "de facto" standard, where there are enough users that do things the same way (or buy the same thing) that it guarantees sufficient resiliency. For example, USB is a committee standard (but if you use A, micro, mini etc. you have to adapt), Arduino Uno is a de facto standard (and there as well, you can choose between Uno or micro, etc.), and its success made possible the clones costing a few bucks.