Ever heard of Embrace, Extend (We are here), Extinguish?
Downvoters: I hope you read the 'Availability' Section of the FAQ. GitHub literally admitted this.
> Can I use it in another IDE than Visual Studio Code?
Not yet. For now, we’re focused on delivering the best experience in Visual Studio Code only.
> Will there be a paid version?
If the technical preview is successful, our plan is to build a commercial version of GitHub Copilot in the future. We want to use the preview to learn how people use GitHub Copilot and what it takes to operate it at scale.
That is a translation to a proprietary lock-in service tied to VSCode, GitHub and OpenAI which is all Microsoft exclusive and it admittedly unavailable on other editors. The extension does NOT work on Atom editor for example.
If that is not a strong case for the 'Extend' phase, I don't know what is.