I don’t know, pretty much all production software I’ve ever used has made a distinction between export and save. Because export takes compute and can change the output, not all formats are created equal.
Saving in the internal format is probably rare if you’re just a user, but if this is a 40 hour a week job, then the compute time savings and potential disk space saving from doing that might be worth it.
The problem not being able to make the save/export decision from the same dialog. A lot of software lets you do "save as" and pick a different format AFTER you go down the File/Save path.
Having to cancel out of File/Save and go back to the File menu and choose File/Export, over and over and over in software that defies this convention, is incredibly irritating.
Saving in the internal format is probably rare if you’re just a user, but if this is a 40 hour a week job, then the compute time savings and potential disk space saving from doing that might be worth it.