It used to be. For instance, France passed a law in 1987 to include an automatic tip on all bills (12-15%), i.e., switched from optional to automatic tipping.

AIUI, French restaurant menus still say "service compris" (service included).

And, FWIW, the top hit about this when I searched for articles on this in French is an article where the hotel-industry association is thinking about getting tipping reintroduced... (https://www.ouest-france.fr/europe/france/restauration-bient...)