This is related to #1903, where we are working on a user activation model. Here I am isolating the discussion on "events that should trigger a user activation" because this looks like a parallel work that can go ahead with or without the model question.

Current Activation section mentions (among other things) a list of activation triggering events. Unfortunately the list doesn't represent the reality. A recent catalog of activation-triggering events in Chrome, Edge, Firefox and Safari shows the big inconsistencies we have today, sometimes even between desktop and mobile versions of the same browser.

We need to fix this.

One challenging point is the possibility that the set of events could be API-specific!