Didn't some market study show that almost nobody plugs their phone into their computer anymore?

At least i can't remember the last time I did.

Does Apple include that cable with either the iPhone or the MacBook though? I consider it to be unreasonable to expect consumers to fork over more money to connect two devices from the same company to one another.

You don't, though, iPhones will sync with the macbook over wifi: the only real problem is that the iPhone won't charge without the usb -> lightning cable or a power adapter.

No, the current expectation is the consumer to buy it :/

The point is people don't want to carry a bag of dongles with them everyday.

Especially the Pro model consumers. It's fine for reduced ports on an Air or MacBook, you're going to make sacrifices for portability. For a flagship laptop consumers expect options.

Meh, I have exactly the same problem with Nexus 6p. I need one USB-C/USB-A cable for data transfer, another USB-C/USB-C for fast charging from the power brick that came with the phone, but back again to USB-C/USB-A to charge from the car. And don't get me started about the lack of good car charges that that support USB 3.1 PD.

It seem some friction to be inevitable when new physical connector is introduced.

Most of those cables are "stationary" though (quotes because your car moves). And a stationary cable isn't that much hassle or friction.

I have a cable that never moves from my bedside, it plugs my Pixel C-to-C into the brick. I have C-to-A cables at my desk at work and at home, neither moves. Your car's C-to-A cable (presumably) doesn't leave your car.

The move to C on the host end is something that hasn't happened recently (not since A took off >10 years ago), but the move to C on the device-end is comparable to the move to the original 30-pin i-device cable, Mini/Micro-USB, or Lightning. It's obnoxious but inevitable.

But don't worry, in 5 years it'll be ubiquitous, like USB-A is now! You'll see it on planes, busses, hotel room USB outlets...all those places which now have USB-A with 500ma charging which are now obsolete. The hotel alarm clocks with 30-pin connectors are especially hilarious to me, since they're "new" but already obsolete. It's still not reasonable in 2017 to travel and forget your charger, and it'll get worse (again) before getting better.

Exactly like the FireWire ports on my older macs.