I think the question has been answered so a different post:
In my humble experience in that industry, "we are, as Oscar Wide quipped, “all in the gutter, but some of us are looking at the stars”.
Using pretty high end pricing here, but from the third world in the early 2000s, so multiply, as you wish.
We comiserated with the colleague who got a $3 dollar tip on a $300 bill, but when she said she gave it back (she felt deeply insulted) we laughed. Customer was noplussed, we thought, that’s $3 less for beer later… better than no $3
Working in an area with multiple tourists from multiple countries, some staff attempted to steer certain nationalities away from their “sections” (group of tables for which they are the respomsible waiter) and into someone else’s. This can be subtle in rush hour, but still fairly obvious.
Now, in general
Indians. I never queried from which part of the subcontinent (or indeed Durban, as I live in RSA) they came from. Rarely tipped. Easy clients though.
South African Black people: expect 10% (or nothing). Cultural differences, it was a newish concept. (Nouveau Rich Black people throw money around as if they were in an American music video, bit they also throw attitude, so at the end of the night - if it is there - that ostentacious display of wealth in ypur pocket feels just right.
South African White people: expect 10 to 15% no matter how good you are.
Sourh African Indian people: round the bill up to the nearest decimal. (Or nothing)
That’s the locals. I worked in a great fish restaurant in a habour, so we got a lot of foreign visitors.
Random, non scientific examples
USA: anything up from 20%, often 30%
Germany: 10% (travel booking details told them) but occasionally up to 30%
UK: 10 to 15%
Anywhere in Asia: 0% (it is not a cultural norm to tip)
Austalia: 0% (no culture of tipping, I think)
South Africa 10%… because decimal maths is easy for us.
Most of those who had read a guide book tipped in the way suggested by their book.
However. Rich people. Of any nation. They either tip extremely well or extremely poorly.