Depending on the coffee or roast, the coffee will do better as cold-brew or Japanese-style iced. Some coffees are absolutely terrible as cold-brew and vis-versa.
That being said, I almost always prefer cold-brew (bias-disclosed).
Furthermore, this article seems to follow a trend in speciality coffee of taking some loose science then jumping to completely arbitrary conclusions. Often it is hard to tell if they are on to something, just want the attention, or have something to gain economically by propagating their view.
You see the same thing with the "third wave" movement who espouse that very light roast is the "best" way to roast coffee. Light, medium and dark roast coffee is all perfectly fine ways of roasting, and all return different flavors for different beans.
I prefer a roaster that has mastered the whole range.
Or we could keep drinking coffee because it tastes good.
0) https://www.kickinghorsecoffee.com/en/blog/caffeine-myths-da...
Cold brew oxidizes, and doesn't extract many of the flavor compounds from coffee. That's why it always tastes kind of stale and flat. Now, you might like that, but I'm sure you can see why many people would say that it's a worse way to make iced coffee.
Similarly with roasting beans---lighter roasts preserve more of the flavor of the beans. So, if you have really high quality beans, dark roasts are just a waste. That's not to say that dark roast coffee can't be delicious, but it's less complex.
Similarly, sangria is delicious, but you probably shouldn't mix your 1982 chateau lafite with orange juice.
I really disagree with the third wave snobbery that the only coffee to be enjoyed is light roast though. There's a pretty wide range that will produce some amazing coffee. Putting them side by side for a cupping is interesting, I personally became more sensitive to roasting too dark after tasting the same beans under different roast profiles, and seeing how quickly the dark range began diminishing complexity, brightness and clarity in my cups. On the other hand, all too frequently I get underdeveloped third wave coffee that is just as unenjoyable as a burnt batch.
I don't think it's that, I think it's because they last longer on the shelf (light roasts go stale faster) and because dark roasts just taste burnt, meaning you can swap out one bean for another and not notice a difference. So if a cheaper beans becomes available, that will get switched in.
Dark roasts are not more shelf stable than lighter roasts though. The oils in dark roasts become rancid substantially more quickly because a darker roast has expanded more, and therefore has more surface area to come in contact with air. Starbucks and other big companies say their coffee is shelf stable for about a year, but the reality is coffee peaks 24-72 hours after roasting. Burnt notes grossly outweigh staleness though. That with the benefits of consistency is great for bigger brands exactly for the other reasons you mention.
To add a bit more perspective, green unroasted coffee beans are considered fresh or in season for about 9 months. The more you get away from this in a roast profile the shorter the shelf life.