Cat CSV, JSON, Markdown or plain text (TXT) are just (file) formats, but that doesn't mean that the app know how to interpret the data inside. Every app can structure their data differently into a JSON... You have to pre-format all that data for Diarly or the other apps to be able to read those files. There is no standard file format for exchanging journal data, so every app has to write a importer for every other app manually.
Cat More concerning to me is I don't see options to export Diarium into standard formats
Diarium exports to HTML, DOCX, TXT, JSON and backs up to an SQLite database. If those aren't standard formats, what is it?