Apple isn't a person, it's a company.

But if Tim Cook were to convince Nintendo to do this (they already sell their own Pokemon Band), they would have to charge more for the app than they do for the band. Likewise, it wouldn't be a smart move for Nintendo and eDNA to make the app exclusive to Apple products.
However, the FitBit is still not as accurate as the Apple Watch for fitness tracking. Considering the Apple Watch is not as accurate as the Microsoft Band 2 or the Moov, neither the FitBit or Apple Watch are great for accuracy and fitness junkies like myself.
The way tablets are moving, I would say 5 or 6 years would be a good time frame for your prediction. Once we get into perfecting 7nm chips, tablets will be able to do almost everything their laptop counterparts can without much performance loss.
The Apple Watch should have more health sensors and needs to be more accurate for fitness, because a I mentioned above, they are trailing behind Microsoft's Band 2 on fitness. Both the Apple TV and the Apple Watch can really help Apple get back on track.