I see it all the time.
A perfectly good scene, shoehorned into just three or four monolithic paragraphs. Or a whole dialogue poured into a single huge paragraph, flat and solid as a concrete sidewalk.
Sometimes a writer will err in the opposite direction, smashing a coherent paragraph into smaller shards just to add more "white space" to the page.
No one remembers the list of rules for where paragraph breaks ought to go (although you'll see such a list on Pinterest now and then). So rather than posting another such list, I've tried my hand at making a comic strip to illustrate it!
Here it is. This is my first attempt to use Pixton. Let me know what you think of it!