For Flatpak, I use vscodium to strip Microsoft telemetry out of vscode.

It works really well, the one downside is that vscode extensions are pretty intrusive. They expect system provided SDKs. So you then have to install the SDKs in the Flatpak container so you have them. If vscode extensions were reasonable and somewhat sandboxed that wouldn't be a concern.

All that is to say, Flatpak works well for this purpose too.