From the side-lines it looks like they're slowly becoming an unstoppable dominant force, what's surprising to me is AWS's / GCP's inaction, they're either asleep at the wheel or they don't see Microsoft's dev mindshare grab as a threat.
And it was should have been rather obvious when GitHub released the beta of Actions a few years ago. Actions remains the most important thing GitHub has done, ever, in my opinion. It might take a few more years for people to fully realize what this could be. Hope GitHub doesn't screw it up!
I don't see what paying Github would do for AWS or GCP. They both have their own code repos, build pipelines, container registries, and more. Even Azure has its own DevOps product.