Consider just how many tiny little successes Thanos had to fight for to finally arrive at the moment where Tony Stark gave up his life to defeat him.
Imagine another universe, where Thanos went to Vormir and gave up the life of Gamora in trade for the Soul Stone.
Imagine his confusion when he did not receive it.
“That’s not what LOVE is, asshole” muttered Red Skull as Thanos was dismissed from Vormir forever, his plan to create the gauntlet defeated completely and utterly by the enemy he never saw coming.
The Enemy’s Name: Failure To Research.
He went on struggle to find another purpose in life while dogged forever by an enraged Guardians of the Galaxy (and an army of decimated civilizations out for revenge) into his own set of tragic stories.
You can read those stories, but you'll have to read them somewhere else.
Back on Earth the Avengers are left to have episodic adventures of their own and grow together, as a family, as friends, and as a team.