I worked on a real-time analytics product based on Snowplow, and I came to the conclusion that bounce rate is fairly meaningless metric (at least, in and of itself). When you are able to track actual engagement based on active time on page, the bounce rate becomes almost worthless as an indicator of success.
We measured "active time on page" based on how engaged the user was on the page: were they scrolling, clicking, moving the mouse on a focused page, etc. It wasn't perfect, but it was much more helpful to publishers than Google Analytics' page-level metrics.