Chapter 2

Why Multichain Exists

No single blockchain optimizes for every use case at once. Ethereum offers deep liquidity and composable DeFi but charges premium fees at peak demand. Solana and newer L2s trade some decentralization for throughput. Users follow apps, yields, and communities — not a tidy map of one chain per purpose.

Multichain is not an accident of marketing — it reflects real tradeoffs in cost, speed, tooling, and ecosystem maturity.

Why chains specialize

Priority	Typical chain choice	Tradeoff
Lowest fees	L2 rollups, alt-L1s	Bridge risk and fragmented liquidity
Deepest DeFi	Ethereum mainnet	Higher gas at busy times
Fast finality	Solana, some L2s	Different security assumptions
Specific apps	Where the app launched	Must bridge assets in to participate

Bridges exist because users want those tradeoffs without abandoning assets or liquidity they already hold elsewhere.

Developers deploy where users already are and where grants, tooling, and liquidity align. A protocol on Arbitrum may expand to Base; a game on Polygon may bridge rewards to Ethereum for trading. Capital and attention flow across networks even when ideology prefers one canonical chain.

Bridges are the plumbing that makes that fragmentation usable. They do not remove tradeoffs — they relocate them into custody, verification, and operator risk that users must evaluate explicitly.