Ethereum is holding top rank 2 by replacing Ripple, and it becomes possible because of growth in Ethereum adoption. There were many coins on the rank 2 but none permanent, which shows that it may be possible that Ethereum can get replaced by other innovative coins.
I'm strongly saying this because technology is growing and many strong coins compare to Ethereum already launched, they are also working on their community growth to hit hard Ethereum, and it is possible they may replace Ethereum so if you missed Ethereum then don't worry keep reading this article I’m going to describe some projects and you can choose your favorite one to go with.
Polkadot:
This is a project founded by Dr. Gavin Wood, one of the co-founders of Ethereum and creator of Solidity language, who left Ethereum in 2016. The primary focus of this project is to achieve scalability and interoperability that Ethereum can't do. Polkadot uses sharding technology to achieve scalability and in Polkadot shards are called parachains that can process transactions in parallel, and Polkadot uses flexible meta-protocol which gives the parachains the ability to determine their own rule.
For interoperability, Polkadot uses bridge parachain technology, which can help to connect other blockchains by offering two-way compatibility. So using bridge parachain Ethereum can connect to Polkadot then an Ethereum Dapp developer can interact with other parachains but the reverse isn't possible, which means Polkadot can't be a sharded on Ethereum’s Beacon Chain. For instance, Moonbeam is a bridge parachain on Polkadot that provides developers with an Ethereum compatible smart contract platform on Polkadot. {Reference}
To grow the adoption of Polkadot it undertakes huge efforts like doing potential partnerships with other projects, running an ambassador program to spread awareness, hackathons for developers, etc. all of which shows that in the long term Polkadot will achieve a good amount of adoption.
NEAR:
This is the project which focuses on the creation of Dapps (Decentralized applications) with high scalability and low fees, which solves one big problem with Ethereum blockchain because Ethereum blockchain is very costly to run Dapps and smart contracts.
A Dapp is a combination of smart contract and codes and according to a report of 2018, if you try to run a simple smart contract without complex logic then it can cost you about $7000, a complex smart contract can cost you up to $45,000, and there is an extra cost to deploy your smart contract to mainnet. For more details, you can read the gas cost from the yellow paper or look at the spreadsheet where all operational costs listed. {Reference, Reference-2}
NEAR blockchain is now open-source and not only cares about end-users by providing high scalability at low fees but also cares for developers because it provides 30% of transaction fees to the smart contract creator if any transaction goes through the smart contract, which helps all developers to set up a business as said in their economic paper.
Apart from Dapp and smart contract, NEAR also focuses on interoperability where you can bring your Ethereum assets to NEAR blockchain through the existing Rainbow bridge and grow the adoption of NEAR blockchain it did 60+ partnerships worldwide, several active guilds with multiple talents like the content creator, developers, influencers, etc are working 24/7 to spread the awareness of NEAR worldwide, with figment learn it creating dev tutorials to easy onboarding of devs, hackathons for developers, etc. {Reference}
Algorand:
This is a permissionless platform-based blockchain working towards building a borderless economy that was founded by Dr.Silvio Micali. Algorand blockchain has innovative facilities for developers to create and run smart contracts or Dapps. As Algorand is an older project than Polkadot and NEAR so it has well-developed tools for developers for instance- a good API, indexer, Algorand studio, sandbox, and Algorand has enhanced SDKs that can help you create and deploy applications on the Algorand blockchain where Algorand has multiple languages (JavaScript, Java, Python, .NET, RUST, and Go.) supported SDKs for a developer in Algorand blockchain, so SDK removes the need to build from scratch. {Reference}
TEAL (Transaction Execution Approval Language) is the platform language of Algorand blockchain, which is a bytecode based stack language used to write stateful and stateless smart contracts. All the programs you create with TEAL should be short and run in-line along with all the important information for signature checking, transaction balance rule checking, etc and read-only access after the smart-contract attached to the transaction makes it the most secure language to write smart contracts. {Reference}
Algorand is very serious to grow its adoption and use cases so it doing partnerships, hackathons, reward-based programs for developers, grants, funding, and mentorship programs like Algorand Asia Accelerator/ Algorand Europe Accelerator programs for startups, partnership program, etc. and 500+ ambassadors are working worldwide to spread the adoption through awareness.
Conclusion:
I agree Ethereum is the first platform-based blockchain so the efforts Ethereum did to grow its adoption is ahead of these projects but if you compare the technology, then these projects are ahead of Ethereum blockchain and in the future these projects must come with more innovative approaches and it may possibly overtake Ethereum. New people are coming with crypto and blockchain awareness grow so they may prefer to go with most advanced technology.