Non-americans don't. To me, being socially expected to tip for a Taxi feels like a parody from a sketch comedy. ditto for tipping barbers or expecting tips over 10%. The only time I've tipped a Uber was when me and my friends were at risk of losing a train. The driver (unprompted) went pedal to the metal to make it on time, so afterwards I gave him a couple of bucks.
Tip culture is bad for rideshare drivers in aggregate anyways. The apps carefully manage the pay of drivers on each market so necessary supply is guaranteed at minimal cost. If a expectation of tipping exists, the platforms simply pay less. Now drivers also have maximize for tips instead of just driving the goddamn car.