In China, drivers are always clear to show you that they are marking the trip as complete, before you get out of the car.

I wondered why, but I guess it's to reassure riders that they're not cheating.

Well, YMMV... A long time ago I took a taxi in Beijing (this was way before Uber was even thought of though). When we stopped at my destination the driver quickly unplugged the meter and then asked me for twice what it said. I knew this because I was traveling on a shoestring and wanted to know how fast the meter went for future reference so I had been looking very carefully at it. Maybe I was just unlucky...

The particular scam you mention is impossible with an Uber-like platform, as payment is made via the app, and there's no way for the driver to massively increase the fare in the last moments of a ride.

"Well, YMMV"

No, your mileage cannot vary, because it's tracked in the app.

Isn't this a story about them doing just that, though?

They do that in Brazil too. I always assumed it was to get rid of the trip soon, so they can take another one.

Or have a way for the rider to normally end the trip. I could imagine a scammy driver with a fake Uber UI with just the "end trip" button.

But the trip will presumably not end on your phone if they faked it.

Or is it not possible for you to say the trip is ended when you get off (and see if the driver disputes it)?