The most important practical detail here is that if you run vscodium, or download and build the vscode repo from microsoft yourself, or use any forks of vscode,

The most important practical detail here is that if you run vscodium, or download and build the vscode repo from microsoft yourself, or use any forks of vscode, you cannot install any of the extensions hosted on microsoft's servers without violating their license terms. There are alternative extension marketplaces such as https://open-vsx.org/ https://open-vsx.org/ but they are missing a lot of the extensions, some of which are proprietary.