I'm sure when I was a lad there were only two types of trailer, or at least the ones I remember. First there was a teaser trailer that would only last for about a minute and was quite coy in what to reveal. Although in fairness, that's probably because there wasn't enough footage ready to make a trailer, especially if it contained special effects elements.
The second trailer would later arrive, two minutes at most, containing special effects shots, and it would give you an idea of the film without revealing too much.
What have we got now? The entire film in three minutes to make sure everyone comes to see the film. I don't, I feel like I've seen it and have no plans on watching it now. cough The Fall Guy cough
I agree with your overall sentiment, but I actually was thinking about the trailer I had seen for The Fall Guy as an example of a trailer done with a little more care, before even reading your post. I thought The Fall Guy trailer was cool in that it made you think you knew the whole story but it was a bit of an intentional misdirection. I would have bet $20 going into that movie that I knew the plot ... and lost. I will add the disclaimer that I am typically trying not to pay attention to trailers because so many of them do spoil the movie.
I went back to watch both trailers today after seeing the movie last week. One is a lot of plot points but jumbled to make it somewhat unclear (by design?). The other has what you would expect to be full scenes that I don't even recall from the movie. The full plot is not more than hinted at in either. I enjoyed the movie, and having seen a trailer didn't take away from that at all, in my experience.
Again, the disclaimer: I agree that plot revealing trailer suck. I typically avoid watching trailers in theaters by looking at my phone or whatever just to distract myself, and never watch trailers at all outside of theaters.