If “fairly new” = for at least a quarter of a century then I suppose you’re right. Of course in the end I don’t understand why people whine so much about tipping. I enjoy it, I like having them also work for me, and I like giving them an “adaboy”.
They aren’t working for you, and plumbers and everyone else like cash “attaboys” also, since you are eager to dole out money to employees of other people.