In the past, everyone had been paid a wage for there time, if you had a business meeting or date, to stand out and know your table will be prioritized for best service, it was given before the meal to be priority of the staff not afterwards.
If you did not tip, you are still given good service for a little patience,
Now days as costs of living increase, jobs pay slightly more to appear profitable and have the requirement it is not ok to accept tips, or the employee can now be fired.
Sadly there are those in a business that may be dependent on the tips and support from there customers.