I wonder if part of it was the bias of how the chat apps work with the streaming maybe they use SSE
But I wouldn't discount how uphill it was to probably even argue for something like MCP cause the labs still very scientist-driven and focused on solving everything in token space. The idea that tool use could be super transformative probably wasn't obvious from inside before Claude Code
the deployment targets that got cheap over the last five years are all stateless and a protocol that fights that gets no serverless implementations