The most practical use case for generative AI today is coding assistants, and if you look at that market, the best offerings are third-party IDEs that build on top of models they don't own. E.g. Cursor + Gemini 2.5.
On the model front, it used to be the case that other companies were playing catch-up with OpenAI. I was one of the people consistently pointing out that "better than GPT o1" on a bunch of benchmarks does not reliably translate to actual improvements when you try to use them. But this is no longer the case, either - Gemini 2.5 is really that good, and Claude is also beating them in some real world scenarios.
In a world of zero switching costs, there is no such thing as first mover advantage
Especially when several companies like (A121 Labs and Cohere) appeared well before Anthropic and aren't anywhere close to Open AI