We all agree that the term "lag" lacks a precise temporal definition. That aspect of the term truly is subjective and dependent on personal perception. I have no idea why you failed to notice, but this wasn't disputed by anybody; not I, MAJ71303 or anyone else. So no, we are not misguided, but you might want to read more carefully next time.
I invite you to take your own advise and re-read 11B1P's post below:
Actually, no.
verb (used without object) 1. to fail to maintain a desired pace or to keep up; fall or stay behind
a5cent is actually correct. Lag is the screen response to your input, not from switching between apps.
As you can plainly see, he quoted a dictionary definition of the word "lag" which referred in no way to touch-sensitive interfaces nor user input to an electronic device and yet derived the conclusion that it supported your statements indicating such.
I merely refuted this and indicated that:
a) The term "lag" is a colloquial term which is applied to various forms of unexpected delays with great liberties taken on its true meaning.
b) Words only take on meaning when it is assigned to them. If you (and phone manufacturers) choose to say that "lag" refers exclusively to a delayed response to touch-based input that's fine. However, don't try to tell me and the rest of the internet that this is the sole and truest meaning of the word when I have used it and seen it used in a plethora of other socially acceptable ways.
In a broader sense, all I said is that linguistics is the study of language as is used by humankind, not a set of rules by which humankind must communicate (as you implied by dismissing your fellow poster's interpretation of the word lag)
You included a list of things that the term "lag" may refer to when used in different contexts (network lag, monitor lag, etc). In all of those cases, the nature of the delay being referred to is quite clear, which is equally true of smartphone lag. Admittedly, this sais nothing about the temporal extents of that lag, but that was never the issue.
If this is the meaning you took from my post then I suppose I must apologize for my lack of eloquence, for my point was just the opposite. What I intended to carry is that the term "lag" has many different connotations in many different contexts, but has no quantitative denotation as it applies to any of them.
In other words, "lag" means that there is an unexpected delay in some function. The term itself does not denote what the action is, nor what the expected delay was, and hence is a subjective term.