Storing data and using data are two completely different things. You can store all of FB and lots of other companies in a fairly small volume these days. But as

Storing data and using data are two completely different things. You can store all of FB and lots of other companies in a fairly small volume these days. But as soon as you want to access that data to process or update it the game changes rapidly. Suddenly that one cabinet explodes into a datacenter full of cabinets, or even several data centers. Storage is a solved problem for just about any amount that an ordinary company might need. Getting that data delivered to a CPU at speeds that are still usable in a practical sense if you want to say something about all of that data is a completely unrelated problem which changes amount of technology and funds required from the easy level to the extremely hard and beyond level.