> There's nothing there that would make the coin stable in price versus a fiat currency;

That's correct. The idea would be to make the supply stable wrt. to the hashing costs. Meaning supply would increase with increasing computational efficiency and stay constant relative to it (ie. the inflation of this currency would be tied to improvements in chips).

That puts an upper bound on the value but no lower bound.

Yep, but there's no lower bound on bitcoin's price either...

I’m not talking about Bitcoin, just addressing your description of this scheme as a “stable coin.”

Ok, I should elaborate some more: The initial demand for bitcoin was because of technical curiosity and a need to perform payments outside of traditional payment systems. This demand could be enough to create a lower bound here as well. And contrary to bitcoin a limited upper bound but no definite lower bound would incentivize spending rather than hoarding. Fiat money has effectively the same properties, because central banks will never allow strong deflation but a national currency can lose most of it's value when the economy crashes (see Venezuela).

Bitcoin was cleverly set up as an deflationary currency to attract early adopters. Now, you and I (in line with mainstream economics) may think that a deflationary currency is a bad idea for a state, but there are a lot of people who don't, and it's not actually being used as a state currency anyway, so maybe it's OK.

Anyway, the point is that from the beginning bitcoin was set up to promise massive gains to early adopters, which helped gain traction. Your suggestion has nothing similar, so it's not clear why anyone would adopt it.

Really, it seems like you're promising hyper inflation (because of Moores law), which is something a lot of people flock to crypto to get away from, and nobody (even those who like a little inflation) thinks is a good idea.

Fiat money has properties which your proposed "stablecoin" doesn't, like a reason for people to wish to receive it as payment in the first place (people need to settle debts and tax payments denominated in that currency) and a central bank which acts to reduce the amount in circulation when inflation gets too high (Venezuela's central bank isn't doing that and you've noted the result...).

Incentivizing spending rather than hoarding just means you hit the lower bound (probably zero, unless receiving units of your coin is really, really technically interesting to some people) earlier...