I think in general, they don't live up to their potential. It seems golfers tend to find a "best way" and stick with it over time.
I think there are two types - The forced carry short cut fw on a dogleg and the side by side on a straight hole.
To work as a shortcut, golfers need to be able to save at least 2-3 clubs, the approach distance needs to go from under 180 to over 180 (where accuracy starts to wain), and perhaps some other advantage, like working with the wind, frontal opening, speed slot, etc. This usually requires a 450+ par 4 with a + 45 degree dogleg, and maybe up to 67-80 degrees. Note, Pete Dye figured out later on that it is probably better to guard the short cut route twice, leaving the longer approach shot with some kind of opening for the safe players, not forcing a bogey if they go that way.
Side by side probably requires a wide green, and usually, but not always, the left side favors coming in from the right and vice versa. A gull wing or "A" frame green usually work well on these shots.
I have seen a few where the short cut is an easier route, which doesn't work at all. Shorter and an easier approach? What other choice would I make, unless it was really a tiny target area.
I have also seen some golden age and newer courses where the alternate fw has been converted to rough, not seeing enough action to warrant mowing and spraying another 1-2 acres of fw.
Jeff Schley, I have asked this question here numerous times, but what, in your minds eye, constitutes a wide fw in terms of yards of width? Some would say 40 yards, others 50 or even 60.