For those attracted to VS Code, but who wish to avoid its non-open "telemetry" tracking, there is VS Codium:

Microsoft’s vscode source code is open source (MIT-licensed), but the product available for download (Visual Studio Code) is licensed under this not-FLOSS license and contains telemetry/tracking. . . . This project includes special build scripts that clone Microsoft’s vscode repo, run the build commands, and upload the resulting binaries for you to GitHub releases. These binaries are licensed under the MIT license. Telemetry is disabled.

It's possible that you have Zettlr in mind? And possibly not! But given the high degree of overlap with Obsidian's approach (Zettlr's forums/discussion address this matter in several threads), it's worth noting in this curated post. It, too, is a Markdown based writing + note-taking + idea-connecting (Zettelkasten model) app which is open source and cross platform.