The 'Apple locking in' fallacy is not true at all. I am not forced to make the decision to buy an iPhone, I choose to because I prefer using it.
Of course there are shortcomings in the OS and the hardware, but the trade off is far worse than the shortcomings. iPhone does far better with the hardware and the software. For example, iPhone 6 has smaller battery than the S6 and S6 battery life is still not better than iPhone 6. Apple designs custom SOC for efficiency while Samsung will design a generic processor that runs a generic OS, that is where Samsung cannot catch up to Apple.
Let me turn the tables with a silly question, when will Android catch up to iOS, example http://superpowered.com/androidaudiopathlatency/#axzz3XTduabxD
There is a lock in to the ecosystem. IPhone users hesitate to switch to Android lest they lose iMessage, Facetime, and Airplay with other iOS devices.
As for battery life and performance, iOS is doing a lot less than Android. I noticed battery life has gotten worse as iOS has added features like multitasking and automatic downloads to give an example.
I don't know enough about the audio latency. I haven't noticed any unusual delay at all with music or telephony apps. I don't play games, though.