Traditionally farmhouses are simply homes built on agricultural lands to house and protect who owned or worked the land. The term Farmhouse isn't necessarily connected to a particular style identified by a fixed set of features, but a setting for a way of life. This is most likely why its appeal seems to be timeless.
Technology keeps evolving. And so do the ways architects reproduce reality and help people envision their new home. While we will always need technical 2d drawings for all the steps of the architectural process, the architecture industry now demands more realistic reflections of their imaginations.