Has it occurred to tech people:
The next big mainstream thing may not be anything at all?
IoT adoption is lukewarm at best and most IoT devices are "I bought them and now I replace them once every 10 years" type things.
VR and wearables haven't panned out except amongst nerds.
There really aren't any "must-haves" being made.
Moore's law is finally sputtering out, look at what's going on at Intel.
We *may* well be looking at a future where there /is/ no "next big thing" for a long while.