We tip out of guilt. I literally freaking hate it, and I'm starting to tip less and less and prices go up.
Why should I tip you to pour me a drink? You are literally just doing your job. I don't call up my customers for a tip when I release an update to their program. I don't send them invoices with a TIP line and show how much 15, 18, 20% of the invoice is so they can add on to it.
Tipping culture is literally (1) employers paying their workers as little as possible and (2) preying on peoples emotions.
It's also a completely asymmetric transaction. How do I know if you are receiving below minimum wage or minimum wage/more? How do I know if you are getting healthcare, or other benefits? Yet I'm supposed to just assume you are being paid almost zero and give as much of my money to you as I can otherwise I will feel guilty.
I'm ranting in general obviously, not at you. But seriously people tip out of guilt and thinking people like you are not making very much money otherwise. It's the dumbest system ever.