It's not a dying art, it's "abstracted away". The servos are still internally utilizing these designs. You just don't have to worry about the gritty physical details, just some basic control code.
Yup, it's in the same way that working with transistors is a
dying art. The use of transistors is not dying at all. Millions and billions of transistors were involved in the creation, transfer, and delivery of these words to your screen or speaker.