I don’t know about Steve Jobs and iCloud, but Dropbox is the kind of thing that can become table stakes, requiring a large surface of interface (esp relative to its core functionality) vs someone else fitting it into their existing infrastructure (e.g. authentication and other tools). That’s basically the definition of a feature.
They only survive at all bc so many competitive alternatives can’t be bothered to invest in doing a good job.
Like I said a moderate sized team putting their all, going above and beyond, etc..., however you want to phrase it, will be competitive even against a much bigger company putting in a half-hearted effort.
Of course if they slip and only start putting in a 1.5x effort or something then they won't be competitive.
They only survive at all bc so many competitive alternatives can’t be bothered to invest in doing a good job.