I don't know about "chefs", but line cooks who haven't been to culinary school are generally trained to call this kind of faux-sweetened sweated onions "caramelized." Because, when a recipe calls for "caramelized onions" (and isn't an all-day background task like making a pot of onion-soup stock... which isn't generally something they'll be tasked with anyway), the onions as shown in the video are precisely what they'll be told to make. (Because it's fast. And because, for many recipes, it kinda-sorta works.)

That being said.

Caramelized onions should be a dark (nearly black) and warm brown color, not a neutral clay-soil brown. (Picture brown-sugar boba pearls.) They should have no water content, and should be visibly syrupy in texture. They should smell buttery + nutty + toasty; and should be extremely sweet, in that complex caramel way, with no trace of the original onion flavor remaining.

The onions in the video are none of those things.

These properties are all corollaries of what caramelization is, when it comes to onions: you're not only breaking down starches inside the onion into sugars, but then also fragmenting some of the resulting sugars into volatiles (diacetyl, furfural, etc), while polymerizing more of the resulting sugars into various caramel compounds.

The onions in the video have merely finished the first step: sweating. The cells of the onion have broken down, releasing simple sugars and water; but despite a few minutes' pan frying after breakdown, they're still wet and gloopy (and have quite a bit more cooking to go before they stop being so), because onions contain rather a lot of water, and rather a lot of sugar, and simple sugars are hygroscopic, i.e. they really want to hold onto nearby water.

The goal of caramelization is the same in an onion as it is in candy-making: you need to heat the sugar up until it melts and begins to react with things around it, both building up (polymerizing) and breaking down (fragmenting.)

Sugar melts well above the boiling point of water. So you can't caramelize anything until all the water is gone.

And that's why caramelizing onions takes around 40 minutes. 10 minutes on high heat to sweat the onions (as in the video); 20 minutes on med-high to drive off all the water; and a final ~10 minutes with careful watch-and-adjust temp control to actually caramelize the sugars, without burning them.

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In theory, you might be able to make this process happen faster... but not with any random store-bought onion, the day you buy it. You'd need to 1. freeze, and then thaw, the onion (to break down its cells), and then 2. desiccate the onion (i.e. keep it in a bone-dry environment with convective air) to pre-purge the lysed water from it. The result would be a "ready-to-caramelize" onion that would let you skip the first two phases of cooking. (The result would also now be incredibly non-shelf-stable, becoming a pile of mush after a day or two.)

Some people throughout history (who perhaps originated the idea of being able to caramelize an onion in 10 minutes) may have done both of these steps purely by accident! In fact, insofar as onions are storage vegetables often kept in a root cellar for months before consumption, and insofar as some root cellars can both get to below freezing and be very dry inside, I could see most historical people cooking onions for winter recipes having gotten this "speed hack" for free without even trying.

But an onion you buy at the store will have gone through neither of those steps. Caramelizing an onion the day you buy it will take 40 minutes, full-stop.