I used to prefer Lyft due to the silly SV smugness of Uber, but outside the US I depend on Uber and have come to prefer it.
Lyft should show the total of tips every 20 trips or so they had no chance of guessing who tipped and who didn't. Or openly state that a 15% tip would be appreciated and the passenger knows that it's the ride +15%.
https://help.lyft.com/hc/en-us/articles/213830188-Express-Pa...
Lyft is intentionally fuzzy about ride pricing, so even though the driver total is shown real time, it's hard for them to know how much the rider was charged given surge pricing.
Tipping culture also introduces uncertainty into pricing, and means that nicer people pay more and jerks get to pay less, for the same service.
Why is someone a jerk for not tipping? I pay for service provided - give me a receipt with the amount and I'll pay it, no problem. Let's end tipping, folks...
But it's really hard to enforce, and if you were a waiter who consistently had to ask to be topped off to meet minimum wage, you might be putting yourself on thin ice with the manager.
Also, I happen to be in Madrid right now, which doesn't have a tipping culture, and let me tell you that I've had some pretty bad service here. Way worse, on average, than in the United States.
I don't like it, but it is what it is.
Stiffing someone, legally or not, because you'd like to see the renumeration system under which they're paid change is obnoxious. You're not sending a message[1] and you're not applying pressure where it could influence change[2]. You're underpaying someone who can't afford it, and have no room complain when people notice what you're doing. I personally do believe it reflects on character.
[1] Well, you are... just not the one you intended.
[2] To be clear, I'd love to see tipping go away, too.