It's more about "evil whatever" as a species, than an opinion. Then again, I can't tell what this trope wants to be exactly.

The answer is BOTH. This trope is about the old traditional view of "fairies". And "fairy" was originally a much broader category: goblins, elves, pixies etc. were all considered fairies, and they weren't always (well mostly) nice. Most old fairy folklore is about how to keep them away, because they were considered dangerous. Not necessarily good or bad but alien, something that doesn't understand humans and isn't really understandable BY humans.

The one thing that bothers me about this trope is not about the Alien mentality or the danger they represent, even when used in shallow deconstruction.

It's their invincibility.

all the works that tend to use them put them in another realm, capable of abusing humanity left and right without repercussion (Dresden Files being the most offensive) and the best heroes only managing to outwit them temporarely.

Why this bother me?

Because we had shown to mess with the rest of Supernatural creatures, down to the Gods and God itself. Yet every time the Fair Folk or sidhe appears, they are the ones messing with other people, never the other way around.

Even in modern setting, they can addapt with offensive ease and destroy technology at will while the opposite is impossible.

This veneration to this abomination (when exist the Trope of Lovecraft Lite) is quite vexin, mainly because is so universal in fiction.

This is about Fairies, though early modernization of "Pagan" lore grouped elves with faeries, which is where all of that confusion came from. Elves came from Norse mythology, unlike Fair Folk of Celtic, Gaelic, and so on. Elves were not in this category in Norse mythology, they were indifferent about humanity at worst, and the Nordic versions of Angels at best. Note that the Norse also had the dark elves, which should be noted are actually grounded in mythology, and not just the invention of Gary Gygax or Ed Greenwood... though half of what I've found on them says that they're dwarves (as we think of dwarves as dwarves, more or less) and the other half of it says that they're something akin to gremlins.