This is true for a tour or for a show with established artists. For local bands where no onne has more than a couple of demos recorded, "Headliner" just means who has more instagram followers, but all those people could be in a different city so it's irrelevant.

>unlike buying a product a good service means a good tip

Why? Why isn't the service built into the price? What even is good service?

If I go see a psychiatrist or physician and they make me feel better, offer me coffee, and make me feel at home, then you can say that's great service. Yet no one tips their doctors. We even find that unethical as a society. The reason we tip wait staff is because we know they get paid shit and are guilted into doing so.

We tip waiters 15 - 20% just for doing their job. Rarely is the service "exceptional", because by definition, it can't be.

The fact that it's standard practice is disgusting. I don't think wrong for exceptional service is bad. In the US, you have to tip even if the service is shit. And since they don't show the tax on the final price, you end up postponing anywhere from 20-35% more for a meal or service.