Leaving, to me, assumes you're going to another platform. Most other platforms aren't announcing the removal of the jack, so I think we are relatively safe there.
As far as comparing other platforms to iPhones, we've long discussed removable batteries and storage. Apple has never allowed either. We have always had both options, and continue to have, with the competition.
If you're implying "leaving" as just waiting to upgrade, I may be in that boat and my reasoning is twofold. First and foremost I haven't seen a compelling Bluetooth device worth my money that is good for sporting and getting absolutely drenched. The products I've tried all have their shortcomings, not the least of which are price concerns. I'd also like to see what sorts of adapters come to market. I don't need an incredible DAC for running and I don't expect one. My experience with Apple cables is they fray with lots of use and, if their adapter cable performs like their charging cables do there is no way a single adapter would last me the life of the phone.