The phrase “cogito ero sum” asserts agency, self awareness, and self possessions over oneself as an individual. how is that anything other than a plain and logical establishment of individual self within the natural world (or any context)?

I think, perhaps, the purpose of such a statement is misread and often misused. It is a point of logic, and piece of logical evidence, not a piece of material evidence. And since that evidence is for consciousness and sapiens, not a soul, which is something humans can’t seem to untangle from each other, that’s why people have trouble attributing it to one, the other, or either.

Finally, I would like to stress that, and Socrates would agree, that such a statement is meant to be the beginning of a philosophy, not the end, statement or final declaration. It is a statement intended to begin a conversation, not to shut one down. anyone familiar with the Socratic method would understand this implicitly.