alt Hacker NewsIf Opus is one-size-fits-all, then why Claude keeps the other series? (rethorical).
Opus and Sonnet are slower than Haiku. For lots of less sophisticated tasks, you benefit from the speed.
All vendors do this. You need smaller models that you can rapid-fire for lots of other reasons than vibe coding.
Personally, I actually use more smaller models than the sophisticated ones. Lots of small automations.
Yes, all the major CLIs (Claude Code, Codex, etc) and many agentic applications use a large model main agent with task delegation to small model sub-agent. For example in CC using Opus4.5 it will delegate an Explore task to a Haiku/Sonnet subagent or multiple subagents.