Universal languages like Javascript, C++, Java, and SQL can help you to write a smart contract but a developer with knowledge of universal languages is only one component of a smart contract where smart contracts need a platform for execution.
Here platform plays an important role to run a smart contract so some smart contract platform like Ethereum, Cardano, Æternity, and Algorand are invented their own smart contract oriented languages for their platform because some time Node Js application gets stuck after smart contract deployment {Reference}, C++ is not a safe language to write smart contracts {Reference} and SQL has various server problems {Reference}, etc.
So in this article, I will compare and tell you the best smart contract oriented language that combines with which smart contract platform to become a language that best to write smart contracts.
As we all know, Ethereum is the first smart contract platform that introduced the first smart contract oriented language called solidity, but as this is the first generation of the smart-contract platform, so its pros are smaller than cons.
Majority of ICO lunch on the Ethereum platform, so this is a huge platform to work with, Ethereum defined set of rule for which make easier and less risky for the developer to create smart-contracts.
Solidity gives multilevel inheritance properties and reliable medium to the execution of smart-contract, solidity gives multiple type-safe functions with ABI(Application Binary Interface).
But the main problems with the Ethereum platform is the scalability problem, so when more people use Ether to make transactions than its transaction fees get increased {Reference} hence running of smart-contracts can be expensive in the Ethereum platform, The Ethereum network easily gets overloaded thus sometimes we face slow transactions {Reference}, a recent study of Singapore and UK found 34,000 smart contracts of the Ethereum platform vulnerable to bugs {Reference}.
Cardano created out from scientific philosophy, which is a multi-layer blockchain created to solve problems related to scalability, interoperability, and sustainability. Cardano has 3 layers, the first layer known as the Cardano settlement layer which created to get all transactions on Cardano blockchain, the second layer known as the Cardano computing layer where all the computational work gets done where you can run dapps and smart contracts on the Cardano computing layer.
Plutus is a smart contract oriented language which, derived from Haskell (this is a powerful language to solve critical problems)created by Cardano so to write a smart contract on Cardano blockchain you should know Haskell so can easily learn Plutus but the problem is Haskell community is not so big {Reference}.
The major point to think about Cardano is this is working as a federated centralized project which first violates the crypto rule of decentralization {Reference}.
Æternity is a smart contract platform with the various use case and you can tokenize both virtual and real-world assets using Æternity platform, Æternity blockchain has inbuilt oracle so you can process real-life data on the Æternity blockchain, because of advanced state channels you can easily build applications over Æternity blockchain.
Sophia is the smart contract oriented language from Æternity which was created to give maximum security to a contract, and this language is belonging to ML programming language family so it is simple to code with minimum error.
But the problem comes with Bitcoin NG consensus, which used by Æternity blockchain, In a book of "Information security and privacy" where the author described a combined micro-block chain truncation attack on bitcoin-NG {Reference}.
Algorand is a next-generation permissionless blockchain which solves blockchain trilemma problems, Algorand blockchain uses Pure PoS consensus for mining, which is better than any kind of PoS, and Pure PoS consensus gives true speed.
Algorand's pure PoS gives true scalability because of which the transaction cost remains the same even if the numbers of the transaction go up and more and more people join the network Algorand blockchain becomes more powerful and never the point of network overload come.
With Algorand 2.0 now you can create Algorand standard assets, can do atomic transfers, and can deploy smart contracts on layer 1 of Algorand blockchain which can enjoy all the tools and benefits of Algorand blockchain.
Clarity will be the smart contract oriented language for the Algorand blockchain, which is jointly developing by scientists of Algorand and Blockstack {Reference}.
Clarity is an interpreted programming language which means it not meant to compile, Using Clarity it is possible to figure out which code will execute for any function, Clarity gives you static analysis before the broadcasting of a smart contract which gives you obvious information about the cost of broadcast, a set of transactions that will modify in a particular table, and bugs {Reference}.
This Conclusion part is my opinion that I gain after my research and experience and according to my view Clarity is a suitable language to write smart contracts when it gets combined with the Algorand platform.
As we know Algorand is the next generation blockchain which mainly focuses on blockchain trilemma problems, speed, and cost-cutting where Clarity gives clear predictability to a smart contract deployment, so when both get combined you can easily save your money, time, and efforts.