4) change DNS settings in router to use the pi-hole.
Although I agree, it's not terribly complex to follow the steps. Lack of time to fiddle with self-managing a device seems like it could be a bigger limiter.
Sure, but presumably the type of people who are willing to run their own DNS resolver are capable of changing a setting on their router. There's substantially more effort in de-breaking sites broken by pi-hole or other ad-blocking software than there is in maintaining the blocking device.
Although I agree, it's not terribly complex to follow the steps. Lack of time to fiddle with self-managing a device seems like it could be a bigger limiter.