I am going to say that tipping is a North American thing. Entry level employees are paid poverty wages and expected to make up the difference by somehow enticing customers to make an additional payment. When I travel to Europe, a tip is a small amount because the people who serve me are well paid, it is just a small thank you. A euro on the table is a thank you, 20 euros is an insult
Part of that is because almost anywhere minimum wage for tipped employees is much less than for hourly paid workers