The pattern is that efficiency increases and hyperscale fell the previous incumbent. If the pace of innovation doesn't slow, Amazon may fall to the same forces.

Imagine a virtualized army of engineers that the AI or brain upload future may bring. Maybe that won't happen in our lifetimes, but it will happen at some point if we don't manage to nuke ourselves.

There are probably a handful of other trends that will cause instability and salients to develop in the fitness gradient.