Same here, going on 10 years of marriage. We bought very cheap rings (< $100) basically because "Maybe we'll need these some day?" but so far haven't found a reason to wear them consistently.

I understand the value of an heirloom that symbolizes one's progenitor's marriage. Presumably, that is how the ring tradition originated, and why the durability of diamond is a significant selling point for that use case. But I don't think rings are well-suited to this purpose now and would rather leave some other trinket behind, well aware that the true legacy of the progenitors lives on through the posterity.