Tell that to Bernie Madoff, Elizabeth Holmes and SBF. There are limits on what you can say to people and how you can exchange money.
Then there’re the square terminals that are normalizing up-front tipping for everything, not even just food service anymore. I’m sure I’m not the only person who has tipped up front for something and the service wound up being terrible. So there are three examples of tipping towards the future.
There’s another future component to tipping: in many places there is regulation that states if the tips don’t make up the prevailing normal minimum wage, the employer must pay the difference in salary. I’ve personally never seen this happen and I worked for tips for about 7 years.