Just in regards to Amish (who fascinate me): I ride with them on the Chicago to Seattle train route. Many ( not all) have cell phones. Because they deal with the outside world in business.
One reason they ride on that route is to connect with trains to the Mexican border. They have a hospital in Mexico they go to for medical care. It’s modern medical care. They can’t afford the U.S. medical system for a lot of stuff so they have an Amish-network run place down in Mexico.
Also, here’s a fun fact: the Amish population is growing faster than the general US population. Maybe 500 years from now the USA will be majority Amish.