There are many reasons:

1. ChatGPT has a better UX than competitors.

2. Some people have become very tied to the memory ChatGPT has of them.

3. Inertia is powerful. They just have to stay close enough to competitors to retain people, even if they aren’t “winning” at a given point in time.

4. The harness for their models is also incredibly important. A big reason I continue to use Claude Code is that the tooling is so much better than Codex. Similarly, nothing comes close to ChatGPT when it comes to search (maybe other deep research offerings might, but they’re much slower).

These are all pretty powerful ways that ChatGPT gets new users and retains them beyond just having the best models.