The intent of the recipe is almost always to cook the onions for the time stated. Chefs were referring to softened, browned onions as "caramelized" for decades before the chemists started coming in and saying "well, actually that isn't technically caramelized..."
Except that this is wrong. It makes a world of difference in how the recipe tastes. And you have to be a relatively experienced cook to know to flag this.
"Cooked" onions are generally soft but still acrid.
"Caramelized" onions are starting to get hard again because of browning and are sweet with no acrid flavor at all.
Those are two VERY different flavor profiles.
And that's before we get to the point that we have to wait 40 extra minutes for the caramelized onions while everything else is waiting because you expected that it only took 20.
I gather you think very poorly of chefs and recipe writers, but, really, no recipe-writer tests a recipe by cooking the onions for an hour and then writes "20 minutes" to try and win some speed sweepstakes.
However, I also noticed in Montreal "caramelized onions" actually always meant caramelized onions.
So it's just really just poor terminology rather than a ploy to fool you.
Nobody in America is going to wait an hour for food outside of the high-end restaurants. So, anything with "caramelized onions" would need to prep and store that step with the associated degradation.
The exception was my favorite cheesesteak place (sadly now gone--the owners got old and retired). The owner literally had a row of chopped onions that stretched the length of the grill. As he cooked he would keep adding onions on the far right while moving the entire line of onions leftward--so the onions that got used actually had enough time to truly caramelize. Similarly for the steak, just much faster. When everything got to the far left (steak with cheese (people who want CheeseWhiz could go somewhere else thanks), onions, bun) his wife would assemble the full thing.
It was a thing of beauty to watch them work. And the cheesesteak was glorious.
And now I'm hungry and craving a cheesesteak that doesn't exist anymore. :(
There was a nice article talking about how long it actually takes to caramelize onions. Everything says like 20 minutes when it actually takes almost an hour.
Cookbooks and recipes with rigor are few and far between.