See also Show HN, this exact product is frequently shown as a github link.
The paradigm shift in Ai means what you are making is (1) filling a gap until the primaries implement it, most have it in their pipeline if not already (2) how easy it is to replicate with said Ai using my preferred tech stack
What Anthropic can't offer is to let you use Codex or combine it with Claude Code. That is why we think non ai-labs players have a say in this market.
To your last point, as always there is a buy vs build tradeoff which ultimately comes down to focusing on your core business which we think still remains important in the ai era
it's a nonbinary decision now
Google has a free, open source take on what you are building, looks more mature as well
https://googlecloudplatform.github.io/scion/overview/
My comment about Cowork is more about pointing out a different feature set that will crossover with Code. In example they have the Task related things as an affordance, Code has this coming.
I am not saying that build is always the bad choice, but the tradeoff did not disappear imo