It isn’t that usb-c is a necessity. Hardly in fact but knowing that the EU is forcing the hand to go USB-C that apples eco system is currently a mix of both cable standards which is a sign that it’s coming. Why not just adopt it now? The other core advantage of usb-C is transferring huge files and video for editing purposes which I do a decent amount of. While lightning is fast that usb-C would truly help speed up things even faster. Not a deal breaker per se for most people but video editors or raw file users might care for this. I have a gazillion different cables at home so usb-c or lightning is well moot for me as far as deal breaker decisions are concerned. I can use either interface.