A tendência é a morte das moedas fiduciárias como unidades, mas não diria que a tendencia é a morte da moeda fiduciária como categoria.
Ultimamente comecei a viajar no seguinte cenário:
O Bitcoin se torna o lastro mundial. Mas como a rede não possui escalabiliade nem liquidez para pleno comércio, os países (e bancos) começam a emitir papel moeda lastraeados em Bitcoin (como se fosse uma LN mas no mundo fora da blockchain). Então, algumas instituições irão começar a usar reserva fracionada, que vai levar a um descontrole na emissão sem lastros em Bitcoin e consequente queda de muitas dessas "moedas".
E o tópico de memes começa a desvirtuar...
Isso foi previsto por Hal Finney em 2010, exatamente como você está falando.
Actually there is a very good reason for Bitcoin-backed banks to exist, issuing their own digital cash currency, redeemable for bitcoins. Bitcoin itself cannot scale to have every single financial transaction in the world be broadcast to everyone and included in the block chain. There needs to be a secondary level of payment systems which is lighter weight and more efficient. Likewise, the time needed for Bitcoin transactions to finalize will be impractical for medium to large value purchases.
Bitcoin backed banks will solve these problems. They can work like banks did before nationalization of currency. Different banks can have different policies, some more aggressive, some more conservative. Some would be fractional reserve while others may be 100% Bitcoin backed. Interest rates may vary. Cash from some banks may trade at a discount to that from others.
George Selgin has worked out the theory of competitive free banking in detail, and he argues that such a system would be stable, inflation resistant and self-regulating.
I believe this will be the ultimate fate of Bitcoin, to be the "high-powered money" that serves as a reserve currency for banks that issue their own digital cash. Most Bitcoin transactions will occur between banks, to settle net transfers. Bitcoin transactions by private individuals will be as rare as... well, as Bitcoin based purchases are today.