Great questions. I've pondered them for years. Jeff Bezos told me that a certain planetary alignment has to happen for success, not something you have full control over.
With Steve ==> Apple, I believe the big factors were:
1. Ed Catmull. He is the steady forever CEO of Pixar who stuck with Steve through years of awful failure, and I think he helped Steve de-personalize pushback.
For example, Mike Slade was VP of Marketing at NeXT, my boss, close to Steve for years. He finally had enough and quit. In his resignation letter, he listed three reasons why. Steve stopped speaking to him. Two years later, Steve called him back to say he re-read Mike's letter, and Mike was right. That had never been in Steve before.
So Mike started acting as advisor to Steve but after 3 years of laying people off at Apple plus simplifying and refreshing the product line, Apple's sales were still in decline. Mike went to CES, heard Bill Gates speak about Windows everywhere, and during an offsite with Steve and his direct reports, asked why they couldn't do that with Apple? Maybe they could start with a music player.
2. The planets. One reason we had trouble selling machines at NeXT is they were built on Unix and it was so resource-hungry our machines were too expensive and slow. Apple had tried the same with AUX and failed. By the time he got to Apple, machines could finally power the operating system we had built without choking.
Also, NeXT was asking people to introduce new machines into their mix when they already had Windows, Mac, and Unix. Hard ask. But at Apple, he was reviving their current investment in Apple, a whole different ask.
3. Being incremental. Steve told us all many times that the worst mistake of his life was too many innovations at once with NeXT. He didn't need a magneto optical drive, which ruined the first product intro.
Notice how he got into phones incrementally. First the iPod. Then a phone without third party apps. Then the App Store. All powered, ironically, by NeXTstep. No need to invent a new operating system.