it is a fuel to run decentralized smart contract
Funny that you say that. How can a centralized platform/project fuel a decentralized smart contract? Ethereum is centralized, whether you like it or not.
For OP, ETH is not a coin, it's a Token, there is a difference between the two.
To be concise, a coin has its unique features and its own (original) blockchain like Bitcoin, but tokens, on the other hand, represent an asset (of a project/platform) on top of the blockchain, using another 'layer' of the blockchain like Ethereum.
i am not trying to be political or very precise here, centralized or not, its a token to be used as a "fuel" to run smart contract on blockchain, as in to execute contract you need to give the miners these tokens, as a reward your contract will be executed and written to blockchain by miners
if these contract that need to be executed is valuable, then the token that need to run this contract is valuable too, if it is valuable (even more if it is rare) then there will be a demand, if there are demand and supply there will be trade in this ecosystem, as a result the token will become currrency in this ecosystem
so answering this
But can it be used as currency? Will we ever see children buying ice cream cone using Ether out of their wallet like we imagine will happen with BTC? Or is it unlikely?
it depend, does the ice cream seller need/want to run a contract? if it is then the seller in demand of the token, the seller will be happy to accept ether, and the children will be happy to have an ether because they can trade it with icecream
so in this condition of ecosystem, the ether does have a demand, have a supply, its valuable, it can be stored, it store a value, it is measurable, it can't be duplicated, it is transferable..
does it qualified to be a currency ?
