Mineable crypto is not fiat because it cannot be created or destroyed at will. That is what gives it value over a fiat currency. You don't have to worry about a central government devaluing it or inflating it artificially.
I see your point, you're tying "fiat" to the act of spontaneous creation at will rather than the lack of a backing commodity, but I don't agree that definition, and even if I did I'm not sure it's as cast-iron a distinction as you're implying.
You absolutely do have to worry about price manipulation... the only difference is that it's not specifically governments it's just the disproportionately wealthy. I don't see that as a worthwhile distinction.
Similarly you can destroy cryptocurrency (some at least), and it can be created. The fact that the creation rate is constrained by the prudence of an algorithm designer rather than constrained by the prudence of a central banker seems like another arbitrary distinction.
To me it feels like crypto proponents want a fancy economics term for othering conventional currencies, so the definition is being bent to fit.
History has shown us that relying 'prudence of a central banker' is a really bad idea. Eventually shit hits the fan and they go on a spree printing money. The huge advance crypto has brought us is a solution to this very problem.
> History has shown us that relying 'prudence of a central banker' is a really bad idea
Sorry, no. History shows no such thing.
Just because $BAD_THING sometimes happens under $APPROACH doesn't mean that any other approach would necessarily be an improvement.
> The huge advance crypto has brought us is a solution to this very problem.
Poverty is a problem. Disease is a problem. Quantitative easing is a tool. If you believe that QE is bad, you're free to push for laws passed that take away that tool from central bankers... but you'll have a hard time because it's a very powerful tool for guiding economies.
You may believe that governments can't be trusted with that sort of thing, but Friedman-style laissez faire economics isn't the big success story that many seem to think. The US has become less regulated since Reagan's inauguration and in that time has lost it's position as the world's prime economic superpower to China, a managed economy much closer to the Keynesian model.
You watch how China reacts to BTC. It'll encourage adoption everywhere except within its own borders. Why do you think that might be?
Edit: Fiat just means its value is driven by supply/demand rather than being backed by something like gold.