If at first the components on the boards were huge. The first such as lamps required special installation places. Later they began to manufacture semiconductor elements, their dimensions became even smaller. Now they use SMD elements, small such squares that you see on the photo. The next step is a board printed and consisting of one element, for example as a processor or a microcircuit. Such a breakthrough would help greatly reduce the size of the instruments. Of course there will be a problem with heat removal. As you know, electricity is 100% cause of heat. It is difficult to remove heat from a small size and a fast speed. As an idea, it is possible to use heat to re-produce electricity, and no power is needed and heat is useful. We are waiting for the computer to fit into a matchbox or even smaller.
