It made everything clear back when everything was hand written or done on a type writer. This mattered as paper wasn’t infinite.

Much of modern communication is done in bubbles on screens, so the punctuation doesnt matter as much as it used to.

That said, run-on sentences and word salad are quite common which makes for some entertaining yet stroke inducing screenshots.

The so-called “rules” of language arent actually rules. They are observations. Language use has greatly evolved over time, and schools teach the rules as they know them, forgetting that even a hundred years ago, it was different.