Build a custom index, or just call someone else’s API?
A subgraph / custom indexer gives you exactly the schema your app needs and the fastest app queries, but you build and maintain it. A unified API (Covalent/GoldRush, Goldsky Mirror) lets you read standardized data instantly with no indexer, at the cost of flexibility.
Custom indexer, but far faster to build and sync.
Need a tailored schema and best query performance → build a subgraph/indexer. Need quick standardized reads → use a unified API.