If the writing or symbolic representations were all done on organic materials it would be hard for anything to survive. For example, the Inca knotted ropes. Only the Mesoamericans seem to have devised a hieroglyphic system that has survived because a few organic codices were kept during the Spanish conquest plus extensive use of carved stone architecture and monuments.
What you postulate may be true and it somewhat goes with how Cahokia was built, which was not with stone (at least not large massive stones) which says something about what natural materials were available around Cahokia. Maybe without a lot of available natural stone formations, “organic” materials would have been used for whatever “records” they kept.
Which takes us back to the Inca and it makes me think others before the Inca built many of the massive stone works that have been attributed to the Inca, as I do not see the knotted cords of the Inca as equal to the task of transmitting the sophisticated methods in building the massiv stone works. I think maybe the Inca inherited them and just took them over. Maybe wh they took them over from were peoples who were there during the last ice age.