Going out to eat is normally a luxury so people usually have a little extra spending money to tip.

Taking a Uber/Lyft is out of necessity sometimes and people often don’t have the extra money. If someone is taking an Uber to work because their car broke down and no one else can give them a ride then they are probably not thinking about tipping. If people are going somewhere for entertainment purposes then I’m sure they’ve budgeted in the tip. I’m sure location plays an important role. I don’t live in a big city and most people where I live still call a taxi so my experience with Uber/Lyft is very limited.