If you look at the Marvel Cinematic Universe from a broader perspective, you will see that that all these 22 films over a decade have always led to this one moment - The moment Tony Stark snaps his finger and saves the world.
What you will also realise that Endgame was the grudging admission that Tony Stark was always the only one who would do absolutely everything to save the world.
After escaping from the desert in Iron Man, Tony realised that he needed to do better. And he was equipped to do more than the governments of the world.
And it was that moment that propelled Tony Stark to do the things he did to save people. That sense of obligation that somebody put their life on the line for him so that he could do something better.
But all that soon changed when he met the Avengers. He understood that he was part of a bigger world now.
And when he stared into the abyss as a nuclear missile went off in space, he realised how fragile he and the world he lives in truly were.
It forced him to the edge where he was willing to do whatever it took to save the world.
It didn't help that a year later he saw a vision of the death of his fellow Avengers.
Crippled by that vision, Tony created Ultron, an AI to protect the world that almost ended up destroying all life on it.
But that's a mistake, right? Everyone makes them. Surely, it could be forgiven.
But Tony, burdened with the knowledge of the lives that were lost because he went too far, could not forgive himself.
As a result, he signed the Sokovia Accords to keep himself in check, to keep the Avengers on a leash.
Even when he found out that his opinion was in direct conflict with half his team, he was willing to do anything to keep the world safe. Sure, he blamed Cap for breaking up the Avengers, but deep down he knew the part he played in it.
But he never ran from it. And not for a moment did he flinch. Innocent lives were important to him more than anything else, more than the Avengers.
So by the time Thanos arrived, Tony Stark was as alone as he was when he started.
He went to Titan alone. He fought Thanos and he failed. He lost the closest thing he had to a child. And he blamed Steve Rogers for it.
After all, Steve was the one who had once told him that even if they lose, they would do it together.
Because this Tony Stark was not the man we once knew. He was a broken man who felt betrayed and abandoned by his friends.
When we saw him 5 years later in Endgame, he had tried to give up on saving the world. He had found a family and they were his priority.
He had given up, alright, but he didn't move on. He couldn't rest knowing that there was a small chance that he could take it all back. So he solved the problem of time travel.
Because that's what heroes do.
When he stole the stones and put them on, he knew that there was only one way this could end. And he did it anyway.
And in doing so, he finally proved Captain America wrong.
In a weird sense of a poetic farewell, Tony Stark again did whatever it took to save the world. Only this time, he got it right.
So farewell Mr Stark. Many may don the suit after you and fly in our skies. But you'll always be Iron Man.