Jobs failed hard and was outed in the first place. And he didn't 'come back' he was quite literally bought in with NeXTSTEP. Don't forget $150M from Microsoft and the Office for Mac deal.

NeXT software on lower end Apple hardware was a winning combination.

And the software ecosystem was already in place (even though everything had to be rewritten).

He backed it up with actual product-building merit and enough (but not a lot of) reality-testing. His products were successful largely because of him. Too many copycats forget about the merit part of the equation.

Not all products, NeXT was a major failure, with a few books telling the story how it all went down, only due to Apple's acquisition there was a moment that with Apple's remaining cash, and what was left of OpenSTEP, they managed to survive both companies.

Had Apple gone with Be instead, most likely all three companies would have gone bankrupt before 2000, and Pixar would be Jobs last successful company instead.

I am no Steve Jobs fan but NeXT was amazing and much of the tech is still commercially important today. There is no way you can call it a technical failure.

Where NeXT went wrong is in being astronomically expensive, which drove its addressable market to nothing. This is the exact same mistake Jobs made with the Lisa. The significantly inferior Apple II platform was far more successful.