I believe Agenda data is all stored in JSON format. So it would be possible to write a program to extract the data and transform it in to whatever form is necessary. Whether you have that capabilitiy, or are willing to wait for or hire someone to create that for you, is a different question.
Yes, we do have a JSON format, which is useful for technical people. But we also allow exporting in Markdown, which is a text format. HTML too.
So there are some formats available. But it is always painful to migrate between note taking apps, because they all use different internal representations. Markdown is about the most widespread format, but even that won’t work everywhere, and won’t cover every case.