[kepano]

> The promise that Obsidian will always use markdown isn’t self-guaranteeing.

True, but Obsidian doesn't make that promise. The promise is "file over app": you control the files you create. In this way the promise is not reversible, and self-verifiable.

"...will always use markdown" is not something any app can guarantee. At best an open source app can guarantee it for a specific version (assuming it doesn't require a connection, or the user can self-host the server).