People normally pay tips for a good service. Making tips mandatory provides no incentive to provide a quality service. If the service quality drops - customers will go elsewhere.
People in the US and Canada (where this article is about) pay some tips unless they're pissed. I'm not saying this is ideal, just what it is according to my experience.
Again, the topic is about if this is a 18% price increase. My point is compared to the common practice pre-Covid, it's not. I have no argument about if it's going to decrease the service quality or not.
Wouldn't that be incentive to provide good service?
I ask because some of the best restaurants in the world do not expect you to tip - ie. Danish restaurants Noma and Alchemist.
Europe is another story. Tipping there is not expected. And staff are probably decently paid.