The machines that handle internet traffic are more complicated than the ones that handle cable. Internet traffic accesses more locations and sends information in two directions. Cable is handled by centralized locations and only sends information one direction.
When you subscribe to cable, you are paying to access One Company. They may have a few buildings or servers across a country, but not a huge number. Because this company is large, they make sure that access to their services are stable. When you communicate with these locations, the information is almost entirely one direction. The Cable Company sends information to your house, and your house receives the information and displays it. End of story. The signal going to your house is exactly the same as the signal going to every house that subscribes to that provider. This means that the equipment that handles signals is rather simple – one direction, and all information is the same regardless of location, and it all comes from a small number of locations.
When you access the internet, things get a lot more complicated. You access a huge number of different locations, each location being a different size than others. Some websites are hosted in warehouses by large companies, others are hosted on a Windows XP computer in someone’s basement. When you access websites, you receive information and your computer send out responses – information goes both directions. When you access a website, the information going into your house might be different than information going to your neighbor. This means that the machines handling the information must be a lot more complicated.
Because the machines handling internet traffic are much more complicated than those handling cable there are more components that might jam or fail.