I also thought it was curious. There is a wide range of possibilities for this.

My favorite hypothesis is that OpenAI was navigating the unknown open sea trying to answer the question "Is it possible to achieve this?" without knowing if they would ever find a new land.

The rest of them already know the answer is "Yes it is" so it's not an unknown open sea anymore with a dubious destination. They know it's possible, it's just a matter of money and time. They probably hired whatever engineer was available, and they paid tons of money to come up with a competitive product.