If it becomes a store for more value, the dollar won't be a good unit of account any longer.
Medium of exchange matters if you can't exchange your other MoE for Bitcoin easily and securely/reliably. It will become UoA by default once other currencies fail, or by proxy if it starts being used to collateralize other currencies. nostr:nevent1qqsg9lxjnp6u97xrnsgmft2sra6qdu7ky30l0e5xyuy5y5zrn6gj8vqpz3mhxue69uhkummnw3ezummcw3ezuer9wcpzqf95tyq2jtaug5nue7t4h4qknz8ygnrwfk0nvnz3tpn87pmky0lzqvzqqqqqqyggy8hw