To the extent that all of Apple's ideas in GUIs, mobile devices, music retailing, physical stores, and so on are all "obvious" or "inevitable," Apple's success has been in executing on those ideas with overwhelming competence.
It may sound banal to say that all Apple does is execute competently. But experience with startups shows that executing competently with new products and creating new markets is heinously difficult. And without that execution, progress happens glacially if at all.