Sort:  

In the UK and Australia we use tips as a thank you for especially good service. It's basically a gift of a small amount of extra money on top of the required costs, but we don't often give tips and they aren't expected. In the US it seems to have become almost a requirement to tip, because many people working in serving jobs don't earn a living wage from the pay, so tips make up for a lot of their income. Judging by the screenshot, though, it seems tips are actually the main part of the pay.

Quite informative. It means the tradition and social behaviours have an immense effect on how much a particular work may bring to the table

Yes, tipping makes up the majority of a Dasher’s income. Without tipping it wouldn't be worth doing this service.

It is visible. It's good that tipping culture is there to help you out

For sure :)