The Longevity of Personal Notes

Markdown has stood the test of time in a way that almost any other format you can think of hasn't. How much digital data is going to still exist a thousand years from now? It seems like on the one hand we're able to capture a lot more than we ever have been able to, but how much will be retained is the question. We care about the file that you create in obsidian much more so than the app. The app is ephemeral.