sorry, but that’s not correct. report exports have *always* been in csv .
I would never opt to create any proprietary format unless it’s is entirely unavoidable.
(exception here being the “pdf invoices” extension , which is something different of course and has nothing intrinsically to do with reports as such other than hooking into the reports export hook and adding to the available export format to be able to export pdf invoices for a given timeframe)

furthermore, the detailed report is about as extensive as it gets (in fact it has been made even more extensive a few months ago or so ) , so I don’t really know what kind of information it is you were getting at some point in the past which is now not available.

Please feel free to expand on the subject though as I cannot follow the issue given the details provided (maybe some screenshots or some other examples where I can see the issue you seem to experience…)