Claude Code's success is not due to the agent but because the model is considered the best for programming and is very heavily subsidized, compared to pay as you go API prices. Consumers and Enterprise are not really locked in and will go where it makes the most sense.
I think they have almost no loyalty by actual developers.
When we work trial people, 100% of people ask for Claude rather than Codex or anything else.
When I talk to people at non-AI tech events everyone basically says they use Claude and have not tried an alternative.
Developers writ large are actually not that interested in trying multiple tools, they like customizing their chosen tool and tweaking it forever.
I think developers are as susceptible to brand marketing as everyone else. It's why almost everyone has a Macbook.
Basically you may choose to drink brand A water bottle, brand B water bottle or tap water. Oh and you might choose the glass water bottle if you use API/Fable.
It's not true, it's just a play for margin.