Was it really Icarus's pride that brought his downfall?
Icarus's story is one that speaks to many people's imaginations, and how could it not? The imagery of one litterally reaching for the skies, and tragically falling down is a rather strong one. It's no wonder that so many renaissance paintings focus on this story.
And Icarus isn't alone in his pride, many Greek myths often have hubris (or hybris) as a main theme in their story. From Pheathon thinking he can ride the sun chariot to Tantalus thinking he can trick the gods into eating his own son. The Oddysey has hubris on both sides: the suitors harrass pelelope, thinking they have a right to marry her, and Oddyseus not thanking the gods after they helped him win the Trojan war. Compared to all of these stories, Icarus's pride kinda pales in comparison.
This brings me to Ovidius's telling on Icarus. It's the one I read in school, and is a rather interesting take on the story of Icarus. In his version, Icarus does not talk. (He tries to yell out for his dad while underwater, but fails.) In general, Icarus doesn't seem to be rather proud of anything. His main trait in this story seems to be that he is playful, and maybe even a bit mischievous. The way we see him described is in this snippet:
"puer Icarus una stabat et, ignarus sua se tractare pericla, ore renidenti modo, quas vaga moverat aura, captabat plumas, flavam modo pollice ceram mollibat lusuque suo mirabile patris impediebat opus"
(Ovidius Metamorphoses 8, line 195-200 Latin text sourced from: https://benbijnsdorp.nl/OvMet.VIII.html#VIII,183)
You can read a translation of the entire myth here, but basically what is said in these lines is that the boy Icarus is playing with feathers that were blown away by a breeze, and he softens the the wax used for the wings, playfully messing with his father's work.
The next time Icarus is described doing anything, he is taking delight in his flight ("gaudere volatu", line 223), and becomes reckless beause of that ("puer audaci coepit", line 223). Note that the website I linked translates 'audaci' as proud, which I disagree with, as 'audaci' means something more akin to 'brave' or 'couragous', but can be used deogatory as well, but then it is closer to 'reckless' or 'overdconfident' rather than proud. I wouldn't call it wrong outright as translation is complicated, but I definitly disagree with it. He gets tempted by his desire to fly higher. And then, the wax melts, and the feathers fall from his arms, leaving behind arms, useless for flying.
This doesn't really seem like someone who is particularly proud, does it? He's just a kid, experiencing something that is unique, freeing, and most importantly, fun. It's more akin to a kid playing with a new sled going down a hill that is too steep and hitting his head on a tree than someone who is actively displaying great pride and hubris. Icarus downfall was not caused directly by his pride, but by his mischief.
However, even though Icarus's downfall wasn't brought upon by his pride, pride still played a major factor in his demise. You see, the story doesn't end after Icarus dies. After Icarus dies, the story highlights a bird, laughing at the weeping ex-father. This bird is then revealed to be Perdix, a nephew and former student of Icarus's father, Daedalus. Perdix was an intelligent young man, and quickly became as good as an inventor as his uncle. In fact, soon he had invented the saw, and the compass (the drawing tool). Daedalus, his pride hurt, pushed him of a roof in an act of jealously. Saved by pallas, Perdix was turned into a bird. (Perdix is a family of partridges) Daedalus, however, had to flee from Athens to Crete, where king minos imprisoned him and his son, setting off the events of the story of Icarus.
In Odivius's telling of the story, Icarus does indeed die because of pride. It's just not his pride, and it is not really his story either. The story really puts its focus on Daedalus. He is the one who talks, he is the one who thinks he can overcome both gravity and gravity, and gets punished in a most ironic way. Yes, Daedalus survives, but does he really live? He is free from prison, yet will be forever cursed with the fact that he could not save his son, who is now trapped in the Tartarus forever. Icarus death is a direct cause of his hubrisistic actions.
So no, Icarus's fatal flaw isn't his pride, it is his playfulness and his mischief. But nonetheless, he died because of pride. (at least in Odivius's version of the story)