You get bottlenecked on I/O eventually, and that is the factor that creates jumps to new platforms. Even with modern devices, I/O is a huge point of contention:

You get bottlenecked on I/O eventually, and that is the factor that creates jumps to new platforms. Even with modern devices, I/O is a huge point of contention: we argue for our serial ports and 3.5mm headphone jacks, but we upgrade for the newest USB or DisplayPort iteration. When I started viewing computing in terms of connectivity, the device categories and developments made a lot more sense. We were fine with switches and printouts - except that we wanted to input and retrieve things faster, so we ended up with display, keyboard and mouse, storage media and networking, etc. The Turing Machine parts are important, for sure, but they are most important in pushing the I/O to capacity, and only sometimes get to exercise abstract computing prowess.