OpenCode exists, it is your "open source coding agent" that is practically on par with Claude Code and Copilot in terms of being able to do the 80% of things that most people actually use.

DeepSeek v4 Flash/Pro also exist, they are open weight and on par with Sonnet, just a bit below Opus. Again: practically useful and sufficient for 80% of things most people actually do. And most of the remaining 20% are benchmarks designed to push the limits, not productive work.

Using these already is way cheaper than your typical Claude API prices. What's still missing is a) mindshare - everyone still thinks "claude = coding" and everyone thinks he/she really needs the very best models because he/she is doing such incredibly complex stuff - and b) someone pushing such a stack as a convenient solution for corporations to easily dump their token money into, complete with user management, enrollment, monitoring, all that enterprisey stuff you need if you want to sell to, well, enterprise customers.