Tipping ends when it is legally included in the final bill, in the country you are in at the time. Then any additional tipping would be strictly voluntary.

France for example, includes the tip in the final bill. And the servers are usually career professionals, and not only part-time university students ( working their way through a psychosis ).

A recent restaurant bill I paid in Brasil ( as large as in Europe ) shows the total dining for four people, tax, and a 10 % included gratuity.

But people still tip if they feel the service was exceptional, or they want to.

Tipping jars, if the staff is being paid a suitable hourly wage, gives me the impression that they aren't, and thus getting by on tips alone.