Michael,
I understand what you're trying to say but don't agree.
20 yard wide fairways are incredibly narrow irrespective of the fact that there would be no flanking features.
You're failing to recognize the influence that being in the rough has on scoring, and are focused on the gunsch as the sole scoring impediment.
GCGC has very wide fairways, typically flanked with a first cut of healthy rough with that in turn flanked by really tall, thick fescue that is very penal.
Logically you're right and I suspect that's true for a lot of people. But people are weird (as I'm sure you'll agree) and feelings don't necessarily follow logic. In my head, narrow fairways with a wide swathe of playable rough around them feels wider than wide fairways flanked by water, trees or out of bounds (or gunch, which may as well be out of bounds).
For the pros, roughly speaking (ha) playing from the rough adds about a quarter of a stroke versus playing from the fairway. Given my game and the rough being fairly light, I suspect the difference is around that for me too. OOB adds 2 strokes and water adds at least 1. Given also my propensity to be a little wild at times, my scores will be better on a course where a bad shot costs me a quarter of a stroke than on a course where a bad shot costs me 1 to 2 strokes.
If the rough is heavy, my scoring may be worse, but it still *feels* wider. I know it's not rational, but that's how it is.
Examples:
This:
is a hole with a wide fairway that feels narrow.
On the other hand this:
is a hole with a narrow fairway that feels wide. Probably not in US Open conditions, but for general play I stand on the first tee on Black and I don't feel constricted, even with the trees on the right.
I get that it doesn't make a whole lot of sense, but it's a feeling. I'm not sure it's supposed to.