Folks are free to leave whatever they want of course.
But 15% on the pre tax amount is still the standard tip for normal/standard service.
The service lobby( ) can try to promote a higher average than that-but it will never fly with me-and anyone else who does not buy into their propaganda.

With that said-I do tip more if the service is great and less if the service is poor.

I have also"stiffed" a server for outrageously poor service(it has to be really horrid for this to happen-and it has happned)and I have walked out of restaurants after/before placing an order if something is teriibly amiss(this has happned perhaps twice after placing an order-many times after not acknowladged in a respectable amount of time after being seated.

Many restaurant choices out there.And many folks working in the service industry probably should not be.The true gems should be rewarded generously.