Why is that considred relevant to get a RAG of people digital traces burdening them in every single interactions they have with a computer?

Having locally distributed similar grounds is one thing. Push everyone to much in its own information bubble, is an other orthogonal topic.

When someone mind recall about that email from years before, having the option to find it again in a few instants can interesting. But when the device is starting to funnel you through past traces, then it doesn't matter much whether it the solution is in local or remote: the spontaneous thought flow is hijacked.

In mindset dystopia, the device prompts you.