In both those cases there was a 5-6 year window when the platforms were slow-changing, the dev tools were mature, and disruption was around the fringes, not in the mainstream. From a "learn new tech" perspective those were probably pretty boring periods of time. But from a "solve big business problems" perspective they were amazing periods of time, because everyone felt pretty comfortable using the platforms/tools at hand to actually do something useful for end users.The iPad turned the world on its ear, and we're just now back to a point where it is clear that the platform is .NET/Java on the server and Angular on the client (regardless of the client OS). The server tooling has been fine for years, but I think we can see real stability for client development in the near future - whew!
1. There is lot of fun on databases and cloud computing side.