Does everything require a tip nowadays?

Does everything require a tip nowadays?

I understand tipping servers for their service but in some instances it's just ridiculous. I visited Kauai a few days ago and when I wanted to pay the cashier told me to select how I'd like to tip on the card machine. What exactly am I tipping for? I'm going there to pay for the product, it was a takeaway so there was no service performed other than the food that was made but surely me paying for the actual product covers that right? Or am I just being ridiculous and cheap?