Computers are a material
Computers are not themselves a medium, but rather a meta-medium--a medium from which many different mediums or tools can be constructed.
A good analogy are materials like bronze, iron, and steel. Each of the materials required technological breakthroughs in order to craft things with the material. And each had unique, intrinsic properties that enabled the creation of new types of things. So formative were the capabilities of these materials that historians divide world history according to their advent (Bronze Age, Iron Age, Steel Age), attributing nothing less than the rise and fall of empires to their mastery.
Computers are similar. They have required many technological breakthroughs in order to manufacture at scale and we are still learning how to craft new things with them. The ultimate impact of the computing material remains to be seen, but it is safe to say we are only in the beginning stages.