@ persia
That picture illustrates my point about lack of internal expansion perfectly! Thanks for sharing
I'd make an "educated" guess (based on my own reflections from seeing my own computers throughout time as well as the workstations I work with, has worked with in the past, and those my colleges and friends work with in their respective companies and at home), that 90-99% of the internal slots and connectors in the general PC is completely unused. Even the need for internal hard drives has diminished, in favor of NAS devices, even in peoples homes. You have a very fast, 256GB SSD with operating system and all you applications, and the data on a NAS. A raided/mirrored 3TB NAS where everyone in the family (according to their respective account privileges) can reach everything (from desktops, laptops, smart TV's, smart phones, tablets and whatever), where all photos, videos and movies, music, and other bulk storage resides, is so much better.