However, federate it into "one place" and you have reproducable results and control over the data, even if transient. 100 million documents.. decent sized, doable.
One place just doesn't work for a global corporation, as there are localized laws that prevent it.
It's all good and fine when all linked systems are up and behaving, but one broken or unavailable reference can degrade validity quick.
I prolly sound jaded, but having been called into meetings and seeing Bob blaming remote Jane blaming remote Sally, ad infinitum, gets old fast.
I am sure it does. I have gone into these companies too, and trained them on solutions that do work at scale :)