I'm a little skeptical of any theory that makes pronouns super important for the simple reason that there are many languages like where pronouns are not super important. In agglutinative languages like Turkish and Finnish, person is shown via conjugation, making pronouns redundant. In topic marker languages like Japanese and Korean, person can be derived from context and pronouns are often replaced by titles.
Could you give some examples in context of how this works? I’m interested in understanding the concept!
You can use pronouns in Japanese to clarify the subject or object of a verb, but it's not nearly as common to do as in English. For instance: when addressing somebody politely, you would typically refer to them either by name (with an appropriate honorific) if you know it, or a suitable title (like sensei for a teacher, or okyakusan for a customer). There are situations where you would instead use a second-person pronoun like anata, including as a fall-back if you don't know how else to address a stranger, but it's not at all the default choice as it is in English.
Another way this crops up is through the use of so-called "benefactive" constructions. For instance, hon wo kashite kureta could be translated as "[he/she/you] lent me a book", and hon wo kashite ageta means "I lent [him/her/you] a book". The difference has nothing to do with pronouns; it's that you use a different auxiliary verb when describing something that was done for the benefit of the speaker, or for the benefit of someone else.
Similarly, Japanese has a variety of honorific language which, in polite/formal situations, is used to speak respectfully about others and humbly about oneself (or one's "in-group", such as family members or coworkers). So the choice of wording can convey who you're talking about, without needing to explicitly use pronouns.