Whatever happened to the dream of digital cash?

Why isn't digital cash a thing/usecase anymore?

I started looking back into Nano (XNO) recently. It's one of the few projects still trying to be digital cash instead of a speculative asset or smart contract platform. Transactions are instant, there are literally no fees, and the network has been stable for years now (Even the spam issues were solved). It's literally the modern day equivalent of email for money. It’s kind of wild that this exists and barely gets talked about at all.

I get that it doesn’t have smart contracts or whatever the big thing is currently (I'm way out of the loop). But what's wrong with something that does one thing extremely well. Sometimes you just want something that does one thing really well like moving value quickly and reliably.

The criticisms of Nano have always been:

“It’s dead because the price is low” (Not an argument against the tech)

“It got spammed years ago” (And it was resolved, which most thought wasn't possible)

“BitGrail hack!” (That was an exchange issue, not the Nano network itself)

"Not enough adoption" (This also isn't a tech issue)

So I’m genuinely curious: what’s actually wrong with Nano’s design or its long-term potential as digital cash? Or is digital cash as a concept just completely dead. Because it solves the core issues that make most cryptocurrencies unusable for daily payments.

Would love to hear from people who’ve used Nano (or still do). Is there something I’m missing? Or am I right in thinking it's actually one of the most functional cryptos.

I just want to see digital cash becoming a crypto use case again.