Jane Austen wrote with long winded sentences and long, run on paragraphs. That may have worked with the grammar at the time, printed on paper, and a culture that has more time and less stress.
Nowadays, it could be amusing -to- informative to have a WAG at how much we read on a screen v.s. on a dead tree. Either way, a few ideas can make reading easier, especially for us old bats who are blind in one eye and cannot see out of the other.
One) A broken paragraph is probabley easier to wade through than one which should have been split. I have taken my text copies of P&P, S&S, and Emma and split several paragraphs at optimal places. Of course, such addition edits should be bracketed [ ]. If the paragraph, take more than a screen, it may have a break point. If a sentence wrap more than about 6 or seven lines (Pica 10 pitch, 65 char/line), then look for a run on.
Two) Dialogue is a big stinker when run on into more than one speaker per paragraph. In fact, one speaker may need a break. (see # 1). That speaker may pause, shift their weight, snigger inappropriately, &.
Three) Alike #2, the tag team partner in dialogue need their own paragraph, and a TAG. A tag identify who speak and how it is said. More than two speakers, as in a conversation -to- rhubarb, almost always need tagged for every speaker ID, unless it is plain that two talkers carry the load and a third, who will need ID'd when they interject; "Bovine Scat."
Four) Have no more than two complete sentences in a speaker paragraph, and that is for some setup. Set the scene &c. in previous paragraphs, so that conversation read like hearing a conversation.
Am sure many more helps can be identified. These four are a good start. Ideas?
"The avalanche has started. It is too late for the pebbles to vote." -Ambassador Kosh Naranek