Vitalik talked about the Blockchain trilemma: Scalability, decentralization, security…
What does he mean by that?
No Blockchain can ensure the three important criteria of a perfect Blockchain.
Bitcoin is indeed an infallible and decentralized Blockchain, but it also has a scalability problem, meaning it cannot process a certain number of transactions at the same time without users paying exorbitant fees. Vitalik understood this when Ethereum was facing congestion and exorbitant fees.
This is where he spoke about this famous trilemma, a blockchain can only optimize 2 of the 3 criteria, Bitcoin and Ethereum have optimized security and decentralization, but the scalability issue remains a concern.
Now, how do they manage to be scalable?
This is where layer 2 solutions come into play.
Don't be confused by technical terms, a layer 2 of a blockchain is just a solution to allow it to operate at full speed and reduce fees in the process.
On Bitcoin, we have the lightning network ⚡, it can process a lot of transactions at the same time, something that the original network could not do, either you pay high fees or your transaction will be queued until it's your turn, but with the lightning network, a lot of transactions processed via this network go smoothly without issues.
On Ethereum, we have several layer 2 projects, such as Optimism, Arbitrum, Base, and many others that work to maintain low fees and fast transactions on Ethereum.
The day Ethereum is able to operate without congestion and allow transactions with minimal fees, layer 2 solutions on Ethereum will no longer be of any use.
My article would be incomplete if I did not talk about Solana, the very ambitious project that seeks perfection…
He emphasized scalability and security, these are their strengths. They have refused to rely on layer 2, deeming that they are not really important for the proper functioning of the blockchain but have not sacrificed decentralization either, they have just moderated it a bit; the contribution to PoS on the network is just a bit more expensive than on other proof-of-stake type blockchains.
The blockchain trilemma is still a problem challenging the genius of Vitalik Buterin, but with technological advancements, we may one day be able to solve it, and the blockchain that achieves this first will be the Zeus of the ecosystem.