If I interpret beefield correctly, they're not talking about being able to create new currencies but rather a currency that anyone can mint.

Here's an interesting one, an attempt at decentralized UBI where each individual gets issued individual "coloured coins" and participants accept currency based on a web of trust: https://handbook.joincircles.net/about/whitepaper.html

I think this direction is very worth exploring. Today fiat currency is generated through creation of debt between banks. Most cryptocurrency is generated through validation of transactions (be it PoW or PoS). The idea of moving currency minting down to individuals in a way that can maintain a sustainable inflation is very attractive to me. The really hard part is squaring the triangle of no privileged centralized parties with censorship capabilities while neither being vulnerable to sybil attacks or locking out disenfranchised minorities from the economy.

Circles is the only serious attempt at that I've seen and I'd love to see more innovation and critical analysis in this venue.

There is a GNU currency that is like that but I dont understand how it will ever work with the "honor system" lol I dont see whats stopping me from poisoning the well.

GNU Taler is electronic money, not a currency. Neutral, every one can make its own currency. Transaction is secure (trust in the e-money) because of GNUnet; it even addressed the Sybil attacks concerns.

Trust on the currency comes from real life trust. A bank for the Euro. A human for a novel human-made currency.

Then, Exchanges that trust 2 different currencies can buy/sell those currencies.

I'm not an economist but this also seems like an indirect, peer to peer, way to establish 'credit' of an individual, rather than relying on centralized institutions with dubious security practices, like Equifax. Is this obvious or has someone already thought of this and I'm being dumb? I don't typically hear about this type of application of digital currencies in mainstream media but it sounds interesting in certain applications of peer-determined credit.

You can create currencies that anyone can mint on Ethereum.

That's the trivial part, but without the conditions I laid out above they're neither useful nor interesting, at least to me. FWIW Circles is implemented on Ethereum, if you didn't click the link.

Interesting. How is the value of that currency maintained so that it actually would be an usable currency?

Exactly this.