Self storage of non crypto assets beyond a certain threshold often end up taking the form of other assets like real estate. Purely from a net worth standpoint it's usually not optimal to have cash (physical or banked) on hand above a certain point.

But I take your meaning and it's a valid point: crypto self storage scales better than traditional cash. If scaling of that sort was an issue for me and self-storage a critical feature I wanted then crypto would fill the need. For the moment I'd still avoid using it for that purpose: I don't consider any coin truly stable at the moment, and if a new one came along tomorrow that appeared to have a rock solid foundation then I'd still want to see a few years of history before trusting it's stability. USDC might come close, but can you have self-custody of it, or trade it outside of the Coinbase ecosystem?