An interesting video on the move towards fatter tires.

As a mtb rider, I know there is a difference between tires widths and diameters, some are good and some are not. Every rider needs to evaluate their needs, gains, losses and expectations.

On a road bike, I think there is not as much of a difference to really measure for the average cyclists. It seems to me as "over thought", and minimal for most applications.

As someone who has ridden 28s for decades, loaded and unloaded, I can certainly attest to riding unloaded on 28s over rougher roads allows me to ride faster, more comfortably and with higher and more secure cornering speeds than a lot of roadies on 23s or 25s at high pressures of 110 or 120 or whatever.

I'd already seen their vid, and while it is really talking about road bikes, ie wide is 28 vs 23 or 25, I do see that on a touring bike, wider tires certainly makes things easier on rims and spokes--but it really depends on the road conditions and surfaces.
With loaded bikes, I've ridden with 1.5 and 2in tires, so 38mm and 50mm, and the 38s are certainly a good compromise in my opinion in that they roll pretty nicely on good pavement, but do have the volume at lower pressures to be softer for rough roads.

I think this debate has been around ever since someone invented a new tire size, width or profile. Sure, a wider tire will be more supple on the cracks, bumps and small obstacles on the road but a wider/fatter tire is also means more wind resistance and weight.

I guess the real truth is get a tire for what type of riding you do. I like the way 28's feel on my road bike but they do slow me down a little on climbs, enough to notice. So, I compromise with 25's and feel that works for me but understand that might not work for others.

This debate will never end with just a little effort, we all can find a tire that suits our needs. It really isn't that complicated.

I like fat tires for touring. Touring speeds typically aren't that fast given that you are (a) carrying extra weight and (b) riding a long day. YMMV on this though.

Personally I find a fatter tire makes for a more comfortable day in the saddle and better handling on uncertain road surfaces. Lately I've been riding my 1993 Bridgestone XO 2 a lot lately as I'm getting ready for a gravel event. The bike has road geometry but it's build around 26 inch wheels. I'm running 26 x 1.5 tires; they're cushy on all kinds of road surfaces and accelerate nicely (the rims and tires are reasonably light weight at 400 grams for the tires and 440 for the rims). The bike is plenty fast and handles great. IMHO, this is one of Grant Peterson's better designs:

as you say, there are tires and there are tires.
400g 1.5 tires are pretty darn light, but you could put on Marathon Plus 26x1.5 that weigh 870g and that have a much much stiffer sidewall and tread that would ride completely different to your tires.
Marathon Plus Tour 26x2 weigh 1100g and the Supreme 26x2 I have on a bike weigh about half that, 560g, with a much more flexible body---but it always comes down to where you plan to ride.....

Not a fan of tires that weigh 900-1100 grams. They have their uses for loaded touring (and commuting if you want a flat proof tire) but otherwise I prefer a tire like the marathon supremes (great tires). Also the pasela tgs are pretty darn good and reasonably lightweight esp. if you get them in the folding version (400 grams for 26 x 1.5; 440 at 26 x 1.75).