When would I ever want to copy Jane Austen's voice?
Obviously there are sooooo many occasions when you would want to speak or write like a member of the English Regency-era middle class.
But beyond those, Jane Austen's distancing techniques—using continuous tense, passive voice, nominalisation—might be dated in narrative, but they are standard in a lot of academic writing.
So the ideas you've picked up here will come in handy in formal history and social science writing, as well as dance parties.