1. they don't have the resources to build their own technology and probably never will
2. even if they did have, the best they could do is come up with something very similar to OpenAI's GPT, i.e. a (somewhat) generic AI model. This means that OpenAI can also easily compete with them.
All these companies are doing (if anything) is that they test the market for OpenAI (or Google, MS) for free.