Earlier quoted context omitted.
Going on a tangent, there should probably be a set of universal backup formats that can be advertised as being somewhat portable. So that, if you need to can take your mail and other online business stuff elsewhere if need be. Beyond this article a user might start working for some place that does not allow external app use, but they can bring their data with, to be loaded onto the service. I guess like github and gi…
We do have those formats. Mbox for mail, iCalendar for calendars, vCard for contacts. They're all IETF standards. Google provide data export from nearly all of their services in standard formats. Where no established open standard exists, they provide clean HTML or JSON. https://takeout.google.com/settings/takeout
As someone who has nearly completed their GExit, I'd say I found Takeout to be borderline useless as an export strategy.