Presumably, your country pays its servers a living wage so they don't have to scrape by on tips. This has been the state of the US labor market in most non-fast food restaurants for decades:

A tipped employee engages in an occupation in which he or she customarily and regularly receives more than $30 per month in tips. An employer of a tipped employee is only required to pay $2.13 per hour in direct wages if that amount combined with the tips received at least equals the federal minimum wage [$7.25 per hour]. If the employee's tips combined with the employer's direct wages of at least $2.13 per hour do not equal the federal minimum hourly wage, the employer must make up the difference. Many states, however, require higher direct wage amounts for tipped employees.