All of these companies are too big to fail at this point. They all have at least a decade of reserves to power through anything that gets thrown their way.
However, I do predict that they will change in significant ways in the next decade.
* Apple is one Supreme Court ruling away from ending their App Store monopoly that could disrupt the entire world, since it would also affect all other digital marketplaces.
* Amazon is about to enter a decade of unionization all over the world.
* Google and Facebook both lost a key ability to micro-target on their ad platforms so they are both reinventing themselves to drive revenue from other sources, hardware being the biggest moats they can invest in.
* Netflix has some of the worlds brightest minds in data science and they've built up a war-chest of understanding viewing habits. They've also gobbled up a lot of key Hollywood players in the last few years, so I expect some huge cultural changes ahead as these creatives start to take more leadership roles in the company.