That's true, but Sutskever and Co still have the head start. On the models, the training data, the GPT4 licenses, etc. Their Achilles heel is the compute which Microsoft will pull out. Khosla Ventures and Sequoia may sell their Open AI stakes at a discount, but I'm sure either Google or Amazon will snap it up.
All Sam and Greg really have is the promise of building a successful competitor, with a big backing from Microsoft and Softbank, while OpenAI is the orphan child with the huge estate. Microsoft isn't exactly the kingmaker here.