I don’t know if I agree its a fad, and in some cases a wide channel can indeed bring a lot of relief to a horse… but I do agree its not mandatory and it is very de rigueur. Imhe, channel width is a preference decided by the horse, like most everything else.
I have a horse that has a wide flat back, and I swore up and down that he required a wide channel for spinal comfort, when in fact it turned out he preferred a more narrow channel. Having such a wide flat back, he had the muscle to protect his spine already. A wide channel ended up putting pressure on the outsides of his back muscles, a more narrow channel sat more comfortably … for him … every horse is an individual.
As far saddles of yesteryear, I’ll wager its several things…
one, life wasn’t quite as cush for the equine way back when as it is now. :lol: people didn’t stay up late at night wondering if their saddle fit just right. I remember even just 18 years ago when I started riding it was far more common to see horses with wither sores and white patches at lesson stables than you would now. Back then if the lesson horse was developing white hairs, you just put another pad on. Nowadays, if a horse had a saddle sore or mark at any of the barns I know, it would headline news and people would be trying to get to the bottom of it asap. I think there is vastly more awareness these days.
Two, you have to remember, these awesome 30yr old saddles you speak of were brand spanking new 30 years ago, the panels were likely fuller, softer, springier than what you likely have now, even compared to a modern reflock in many cases.
And, 30 years ago things were built better and there were more craftsmen, less machines and virtually no computers. Trees were still made and built by horsepeople, not by computers and in factories where most of the tradespeople might not have ever seen a horse. The tree is the heart and soul of a saddle. A well made and well fitting tree can make even the most apologetically paneled saddle comfortable enough. (I personally suspect the trend for therapeutic padding and high tech panel design and materials is driven by the decline of the saddle tree craftsman… but I digress).
Remember too, fitting was likely a simpler affair way back when, there wasn’t such the enormous range of breed x’s with different body styles presenting fitting challenges. And finally, I’d wager that aside from the odd cropout breed crossing disciplines, there was a lot less intermingling of breeds across disciplines, meaning QHs basically did QH stuff, TBs did their thing, Drafts had their niche, etc. So jumping style saddles were built to fit jumping style horses, and dressage saddles for dressage horses, etc, etc. All the square pegs went in the square holes, and the round ones went where they were meant too, life was much simpler.
just imho.