I think that rhetoric of "dust" or "data exhaust" is misleading if not plain toxic.
This data trail, "behavioral surplus" was engineered. It is *extra* data that is not necessary to operating the services people think they are consenting to use.
New streams of data being generated, extracted, exploited and re-purposed for surveillance and behavioral prediction.
It's a strategy, examples are numerous. Zuboff's book is essential to understand this.