A lot of new and popular features in VSCode are only available in the official MS version of VSCode. Using any of the forks of VSCode thus becomes a lesser experience.
Microsoft Embraced by making VSCode free and open source. Then they Extended by using their resources to make VSCode the go to open source IDE/Editor for most use cases and languages, killing much of the development momentum for none VSCode based alternatives. Now they're Extinguishing the competition by making it harder and harder to use the ostensibly open source VSCode codebase to build competing tools.
> Embrace: Development of software substantially compatible with an Open Standard.
> Extend: Addition of features not supported by the Open Standard, creating interoperability problems.
>Extinguish: When extensions become a de facto standard because of their dominant market share, they marginalize competitors who are unable to support the new extensions.
As I see it, there no open standard that Microsoft is rendering proprietary through VSCode. VSCode is their own product.
I see your point that VSCode may have stalled development of other open source editors, and has proprietary extensions... but I don't think really EEE fits. It's just competition.
To add to this, there are also official Microsoft extensions to VSCode which add absurdly useful capabilities behind subtle paywalls. For example, the C# extension is actually governed by the Visual Studio license terms and requires a paid VS subscription if your organization does not qualify for Visual Studio Community Edition.
I'm not totally sold on embrace-extemd-extinguish here, but learning about this case was eyebrow raising for me.
C# extension is MIT, even though vsdbg it ships with is closed-source. There's a fork that replaces it with netcoredbg which is open.
C# DevKit is however based on VS license. It builds on top of base C# extension, the core features like debugger, language server, auto-complete and auto-fixers integration, etc. are in the base extension.
Microsoft Embraced by making VSCode free and open source. Then they Extended by using their resources to make VSCode the go to open source IDE/Editor for most use cases and languages, killing much of the development momentum for none VSCode based alternatives. Now they're Extinguishing the competition by making it harder and harder to use the ostensibly open source VSCode codebase to build competing tools.