Anthropic's API has two nines availability and Claude Code is a TUI made with React that can regularly consume more than 1GB of RAM, and the codebase is utter slop. They couldn't fix the flickering bug for over a year!

And yet, Fable and Opus are among the best coding models out there (matched only by GPT5.6 Sol).

It's not about the people there being smart or not, it's about their and the company's priorities, resources and what they choose to focus on.