It is still 13 years from now. Anything could happen. It can be the sixth largest reserve currency or it can be deactivated because it failed to scale.
Bitcoin can become a reserve currency.
Actually, to be a reserve currency, it *doesn't have to scale*. I think that if bitcoin doesn't "fork to death", this is its possible fate. Bitcoin, as coins, will be locked up in financial institution's vaults. No mortal will ever transact on the block chain. The block chain will be another, extremely expensive, commodity, that serves as immutable ledger for many things. I don't even know whether the value of kilobytes on the block chain will be worth more or less than a bitcoin. It would be mightily expensive to do a transaction of a few bitcoin on the chain. Only large settlements between financial institutions world wide will be able to afford such transactions. Bitcoin will be entirely fiatised, and, because of its financial importance, be totally put under international control. Mining without a licence will not be possible.
Bitcoin can become the immutable ledger of the world.
It might also be that the bitcoin token itself becomes irrelevant, and what is the real value of bitcoin, is the room on its block chain. If the kilobyte on the chain is more expensive than a few hundred bitcoin, say, then the real commodity is room on the chain (for other things than bitcoin transactions: that would be a waste !). Bitcoin's coin value will then essentially plummet to zero, but will be used as an "app token" to write stuff on the chain (where you pay a miner in fiat or another token for the room taken).
The "internet money for normal people" dream will be entirely over with bitcoin. This will be left to alt coins that have scalable systems.
Or it might be that bitcoin will fork, and fork, and fork, to make many derived alt coins.
