Many doctors use scribes to increase their efficiency and increase their billing. That is also why many hospitals will cover the costs of scribes for some of their doctors. If they can see 25% more patients and have improved billing practices, you pay for your scribe several times over each year. I have found that many older physicians or less tech savvy physicians utilize scribes very effectively in their practices because they are unable or more often, unwilling to learn how to use their EMR efficiently/effectively.
Personally, I can document in my specialty relatively quickly, but I also spent 200+ hours customizing literally thousands of templates for people in my and closely related specialties. Many EMRs will allow you to front load a lot of your work, but it requires not only time, but dedication toward maintenance which many physicians don't have.
You have to remember that the majority of physicians are in private practice. There are a great many different ways that people have their practices setup. While increasing more challenging, there are still a large number of physicians that own their own practices and any support staff come directly out of their practices profits. Thus effectively lowering their income if they don't increase their revenue by hiring those new people.