For this discussion, to avoid getting tangled up in definitions, let's use the relevant Marion Webster definitions of the two terms.
Atheism: 2
a : a disbelief in the existence of deity
b : the doctrine that there is no deity
Agnosticism: 1 : a person who does not have a definite belief about whether God exists or not.
full: 1
: a person who holds the view that any ultimate reality (as God) is unknown and probably unknowable; broadly : one who is not committed to believing in either the existence or the nonexistence of God or a god.
Atheism | Definition of Atheism by Merriam-Webster
Agnostic | Definition of Agnostic by Merriam-Webster
What I'm wondering is why we insist on separating these two terms, and why and to whom this separation matters.
To put it very simply, how is "not committed to believing" any different than "disbelief"?
From the point of view of the traditional theist, both parties are equally damned as unbelievers.
From the point of view of the agnostic or the atheist, both of them are unbelievers as opposed to the theist.
Why the need to separate two sides of an argument into three when the practical results of doing so do not fundamentally change the results on any side.
If you think they do change the results, how?
I have further clarifications on this thought, but perhaps they'll get fleshed out in discussion.