Waste...
Apple argued any move compelling it to ditch the Lightning port, which has been a staple of the iPhone for almost a decade, would inconvenience its customers, simultaneously creating an "unprecedented volume" of electronic waste.
You mean, just like when they abandoned all those 30-pin peripherals and went to Lightning?
The idea behind this is, you don't need a new charger with each new device you buy, they are standard, so you can share a charger between several devices. That produces less waste... In fact, my Huawei watch, my BT headphones and several other devices all came without chargers, because they all use a standard port (USB-C or Micro-USB) and I just use one of the dozen or so chargers I collected over the years; well 4 now, we had a big electronic clearout last year and brought all the old phones, chargers, hard drives and other Elektroschrott (electronic rubbish) to the recycling facility.
I now have 2 chargers in the kitchen, with USB-C and micro-USB, a charger with micro-USB upstairs and a spare charger in a draw in my office.
And it is more about the wall-wart end of the equation, moving that from USB-A (which Apple also uses) to USB-C. USB-C on both ends would be just be an added convenience, as you only need one cable as well.