Apple will dominate the market until the market itself becomes irrelevant. Good news for Apple is that in the next 5 years I don’t see something in the horizon to challenge the market of smartphones.
After the galaxy note 7 disaster and the apple throttlegate I think it is time for us all to admit the fact that we have reached the limits of lithium batteries. We need to compromise the size of our smartphones if we want to continue seeing progress in their performance and features.
The elephant in the room that no one addresses is that Apple offers 3 year extended warranty programs for which they refuse to fix the malfunctioning batteries by claiming that they pass their tests. This is despite the fact that the tests ran by the phone obviously fail (let's assume that Apple indeed checks the status of our batteries and is not applying blanket throttling) leading to the frequency limits.