Four questions get you to the right tool fast.
Ask: (1) Do you need decentralization, or is a managed service fine? (2) EVM-only, or non-EVM too? (3) How much does backfill speed matter? (4) Do you want to write code (TypeScript/AssemblyScript) or just call an API? Your answers point to one or two options.
Choose when decentralization and ecosystem maturity matter most.
Choose when EVM speed and TypeScript DX matter most.
Choose when you just want to read data via an API, no indexer to build.
Decentralized: The Graph/Subsquid/SubQuery. Self-host & fast: Envio/Ponder. Managed: Goldsky/Alchemy/Ormi. Just an API: Covalent.