Plus many restaurants with placeholder tip icons that start at 25%+
You also don't know what the tip is really going towards in many cases. In the classic restaurant/waitstaff case you can reasonably expect it to go to the workers, in the random knick knack or general goods stores ???
Tipping in general is a system to transfer wealth from the charitable to the uncharitable (high tippers pay more and subsidize the business, low tippers pay less).
I believe in the spirit of tipping rewarding better service, but by and large it doesn't actually function that way. Most tip ~20% on everything outside of extreme circumstances.
Much better for everything to be baked into the price of whatever good or service it is.