Increasing I have thought that trailers give too much away. Almost that they are an actual project. With the films tailored to what can be in the trailers. Closest comparison I can think of is a short film or music video. But that is not the point. Its supposed to be an ad for the actual work.
This does what a trailer is meant to do. The problem with the other approach is it often backfires. A few isolated great moments that spoil the film. Or misleading because a few great moments doesn't mean an overall strong narrative