2018 will see the introduction of bitcoin tech that will enables bitcoin to compete with other coins. This tech is currently undergoing testing and will be rolled out in 2018.
Ethereum (ETH) and Neo (NEO) can be replaced with the RSK which is the first open-source smart contract platform with a 2-way peg to Bitcoin that also rewards the Bitcoin miners via merge-mining, allowing them to actively participate in the Smart Contract revolution. RSK goal is to add value and functionality to the Bitcoin ecosystem by enabling smart-contracts, near instant payments and higher-scalability.
Website – https://www.rsk.co
Monero (XMR) and Zcash (ZEC) can be replaced by TumbleBit. TumbleBit is a new anonymous payments protocol that is fully compatible with today’s Bitcoin protocol. TumbleBit allows parties to make payments through an untrusted Tumbler. No-one, not even the Tumbler, can tell which payer paid which payee during a TumbleBit epoch. https://github.com/BUSEC/TumbleBit
Litecoin (LTC) can be replaced by Lighting Network. Lightning Network is a protocol for scaling and speeding up blockchains. It was designed to solve some of the technical limitations of the Bitcoin blockchain, but could be implemented on top of any blockchain. Lightning Network can enable near-instant transactions, at a rate of thousands to millions per second, with fees of a fraction of a cent (or even free).
This will not make any particular coin redundant, but it may eventually make exchanges redundant. An atomic swap is a direct trade between two different coins running on two separate blockchains; there are no centralized-exchange websites or other third-parties required for this trade. The technology enables common users to bypass the labyrinth of website-exchanges currently necessary to purchase cryptocurrencies. Once implemented, the atomic swap will allow common users to trade and purchase any desired coin directly within their own wallets.