My take on what the Phantoms really is. (It's silverfish)

[smoky marten]

Doesn't make much sense, i'm aware, but if you took the Phantom design, then take out their wings, what do they look like? A worm. The Phantom design has always been a weird one, it doesn't look like any bird or other flying animals. They have no legs to perch on, it's just one long body with wings.
We know there are cases like the piglins, where they were originally pigs that became humanoid-bipedal on the nether and then becomes zombified back in the overworld. Silverfish might have underwent the same evolution process similiar to the piglins.
"But phantoms don't spawn on the Nether" i hear you asking. Well, where do you often find a silverfish spawner? Near the End portal. This would also explain why the ingredient needed to fix an Elytra is the Phantom membrane, in fact Elytra might have been taken directly from the Phantoms themselves, with little modifications to allow for human flight.
After all the Elytra was the builders product, it doesn't look like anything that comes naturally from the End where their main way of transportation is to simply teleport. (save for skulkers that makes things float, but that's not really a way to travel is it? more like a defense mechanism)

And that's my take on what the Phantoms really is. As for why they specifically targets sleepless people however, i have no clue. Maybe just a preferrence in hunting? Maybe they were originally breeded and trained for search and rescue like RGN suggests? idk, but i'm very certain that Phantoms really is just a flying bug.

[shell sleet]

But because phantoms don't have legs, aren't they tired of flying all the time because they don't have any rest?

[delicate yew]

This sounds like a solid theory, there’s just one major flaw: the Bane of Arthropods enchantment. This enchantment effects Spiders, Cave Spiders, Bees, Silverfish, and Endermites. It does not affect Phantoms.

Otherwise I really like this theory, it could be possible that some Silverfish were affected by the End presence and evolved beyond Arthropodic attributes and this became its own beast, the Phantom, but it’s difficult to confirm or deny

[coral moth]

Unless they have a magical ability that dosent allow them to get tiered or that is the thing that allows them to fly

(Phantoms wouldnt be the qst case of an organism having magical abilities, because dolphins and etc also have magical ablities)

[smoky marten]

Phantoms classifies as undead mobs, so maybe they're just too dead to even feel tired i suppose.

Or you can think of them as simple flying snakes i suppose, when they're not flying they just fold their wings and just slither around.

[forest flax]

phantoms have bones. arthropods do not.

or rather, arthropods have an exoskeleton

the phantom has a visible skeleton but only because it is undead

[oak fern]

dont phantoms have skeletons?

wait, i wears its skeleton outside, like an exoskeleton..

wait a second, what if silverfish are endermites that went to the overworld?

[gusty gazelle]

thats a lie

stop spreading misinformation

we all know its from goldfish

[smoky marten]

That would make sense too, never thought of that

Also for the people that's been saying they look nothing alike, pls note that i said "they went through a jump in evolution the same as piglins"
Because pigs and piglins look nothing alike except for the fact that they're both pigs.

Why am i getting worked up about this, it's just a dumb theory.

[frail crown]

If I had a nickel for every time someone related phantoms to silverfish, I would have two, which isn't much but it's weird it happened twice

[supple viper]

Im aware that this is more of a personal take, but i'll give my opinion since its under the theory tag

It doesnt make sense like you said, there's the fact that silverfish are anthropods while phantoms arent like others have pointed out. I disagree that piglins are overworld pigs that evolved, but at least pigs and piglins share elements like sounds and snouts. Phantoms and silverfish dont share anything in common. Removing the wings doesnt prove anything since wings are an essential part of phantoms. Also, phantoms dont spawn in the end, making an already weak connection to the elytra much weaker. Phantom membranes fix elytra, but thats more likely just due to the fact that membranes make up the wings, therefore being useful to repair another pair of wings

[supple viper]

The opposite is more likely. There are more connections from the overworld to the end than viceversa

[coral moth]

Also, you can repair things with materials that the thing isnt made of, like something made out of clay being able to be repaired with glue

[supple viper]

Yes

[ivory knot]

Interesting take however it kinda contradicts how the devs intended for it to be a result of a nightmare or as they called it insomnia

[coral moth]

-do you know what insomnia is ? lol
-how can something imagionary drop physical objects that can change other physical objects ?

[frail crown]

How can you even kill something imaginary at all

you hurt them physically, which in turns damages your weapon

[coral moth]

You can get the illusion that you are hitting something

[frail crown]

mt{wtýuu800o

[fallen cave]

Well as we know Silverfish ARE endermites

Just affected by its surroundings with the end and hauntings

[coral moth]

Where tf was that confirmed ?