I've turned permabear
. Bitcoin will be replaced by a POS-coin distributed by a government or a really large organisation, here is why:
All traditional currencies have something in common: they were initially created by an authority in which a lot of people put their faith in, an authority which they didn't mind would benefit from the inflation/creation of the currency. Sure, many of said currencies were officially backed by gold, but people accepted that the backing inevitably would get fractional.
Bitcoin is mostly issued by lucky early adopters / mining-speculators, which is exactly the kind of people that society would hate to see benefit from currency issuance.
The advantages of the incoming competition will end up making bitcoin worth nothing more than collector's stamps. The fact that the competition isn't visible or even existent yet, doesn't mean than it's not coming.
We will see the benefits of cryptocurrencies for humanity, but it won't be Bitcoin, or any of todays altcoins.
The question is when does the collapse of Bitcoin start. Could be 5 years or 5 weeks from now.
Gold, silver, copper, diamonds, emeralds, gems, rocks, pebbles and dust have never been created by an authority and are "decentralized".
True, but they're not cryptocurrencies, so, they require a trusted third party in order to be programmable, be sent over the Internet, etc... These third parties tend not to survive the regulatory pressure (see E-gold).
Bitcoin is a commodity not a currency
It's both. Currencies are merely commodities used for the exchange of value. Their scarcity is ensured through physics (metals), mathematics (crypto), or trust (fiat).
because as you've already stated currencies are "issued". You should be worried about paper, stocks, fiat etc collapsing to zero but not commodities whatsoever.
The scarcity of fiat is alway temporary, so yes, it will collapse eventually. But it will take a lot longer than most doomsday prophets say.
What is "it" exactly?
"it", is the cryptocurrency (as in decentralized and open-source) which will reach critical mass and, in a hundred years or less, replace the USD. "it" is what many hope Bitcoin to be (myself included), but unfortunately won't happen.