The Newton is an interesting foil.
Why wasn't the Newton the first smart phone? Early internet, barely a high-speed cellular infrastructure, silicon not quite small and efficient enough, no lithium batteries, cost....
Saying the Newton was "ahead of its time" is really a way of saying all the right bits and pieces weren't there yet.
We'll know what the next "big thing" is after it happens. You can't force it though regardless of the dollars you have for R&D.
Just MHO.
They almost did it with wireless speakers (the HomePod is an absolute engineering marvel, entirely unparalleled as a speaker), but they left out bluetooth in a platform play for AirPlay on their own phones/tablets, and it basically flopped. It would have been an airpods-level success if it were a record player that could play everybody’s records.
People keep talking about how they might do it with cars, or televisions, or glasses, or whatever. But so far, as yet, that has failed to materialize.
Edit: I left out the watch, despite it being the best selling watch. It isn’t as better than a normal watch as an iPhone was better than a blackberry; it is merely sufficient: great, but certainly not insanely so. If it could support Google Assistant instead of Siri, and had better bluetooth device support, and didn’t require an iphone, it might be. But the watch presently really just falls short of the Apple level expectation for a product. To be fair, that level is literally “insane”.
I mean they just did that with smart watches and earbuds, under Cook. They are totally dominating those categories with uncontroversially the best designed products. Not good enough for you?