Alternate theory: they figured out teleporters and keep horses mostly to trick the English into thinking they have nothing worth colonizing them for, but also to keep their buddies in the buggy industry in business and because they like horses. Mostly that last one but the other two reasons are still important.
Amish people can hire people to drive them around. Amish contractors sometimes have their own trucks, and use them to interact with the English.
Alternate theory: they figured out teleporters and keep horses mostly to trick the English into thinking they have nothing worth colonizing them for, but also to keep their buddies in the buggy industry in business and because they like horses. Mostly that last one but the other two reasons are still important.
The horses are the ones that open up the interdimensional portals. Obviously.
Thank you!