Currently the Event Timing spec uses an ad-hoc list of events to try to capture those which may be directly caused by user interactions: https://github.com/WICG/event-timing. This is prone to become obsolete over time unless the list is evolved while considering every new event type being created. Therefore, it would be preferable to have this list provided by UI Events, possibly in the form of an internal slot or associated concept of an Event. See w3c/event-timing#49.

Relatedly, we've tried to use certain kinds of events as determining that a meaningful user interaction has occurred for Largest Contentful Paint (https://wicg.github.io/largest-contentful-paint/). However, we query the isTrusted boolean and that is not sufficiently accurate, as for example trusted scrolls may be created from JS APIs. See w3c/largest-contentful-paint#56.