Eventually someone will disrupt them. But there will be a long time span before that where they can compensate for their lack of innovation by buying out possible competition with a lot of money.
There's also the possibility that they just don't get disrupted. The entire computer industry is less than 100 years old. Who knows if the next 100 years will be anything like the last 70.
Of course, there might be a long history of larger companies getting disrupted by smaller companies outside of the tech industry, which would be much more compelling evidence than MySpace losing to Facebook, IBM losing the PC market to Microsoft, Microsoft losing mobile phones to Apple/Google, etc.
I am not willing to make a bet as to whether or not we will still be talking about Microsoft, Apple, Amazon, Google, or Facebook 25, 50, or 100 years from now.
I wonder how things would have worked with Microsoft if they hadn't got into trouble with governments in the US and Europe in 2000. There may be no Apple today and the internet may be their network.
Even if they eventually fail or are disrupted, their massive and ever expanding troves of data aren't going to go away. Somebody else is going to take possession of the valuable data. If nothing else, then govt will acquire them for intel.
Of course, there might be a long history of larger companies getting disrupted by smaller companies outside of the tech industry, which would be much more compelling evidence than MySpace losing to Facebook, IBM losing the PC market to Microsoft, Microsoft losing mobile phones to Apple/Google, etc.
I am not willing to make a bet as to whether or not we will still be talking about Microsoft, Apple, Amazon, Google, or Facebook 25, 50, or 100 years from now.