Is tipping an obligation in the US?

It’s never an obligation, business owners are just trying to get you to supplement their staff’s income at your own direct expense and discretion. That said, it’s more expected at sit down restaurants, you may get hostile looks or words if you don’t do it in that situation. Literally nothing will happen if you don’t tip in situations where you are not being served (fast food, coffee shops, self serve, etc.). I don’t think most Americans tip in these situations.

While not obligatory on the patron to tip, the pay of waitstaff assumes they are being tipped. While the employer legally has to make up for a person’s hours if the total goes below that of everyone else’s minimum wage, anyone who doesn’t consistently make their paycheck from tips is considered a bad server and likely to lose their job.

The problem arises where places that shouldn’t be paying their workers the lower waitstaff minimum wage, are. This means that you never know if a person serving you relies on tips to make their living and adds a moral or social pressure towards tipping in places it normally wouldn’t be done. Companies view this as free money when their workers don’t get the tips.

There is technically no obligation to tip. There is societal pressure to do so that is being exploited.

Its a social disease at this point. I get a lot of shit but I’ve completely quit tipping unless something extra happens. I’m not gonna tip the guy at the pizza hut counter who can’t be bothered to hand me a few napkins without asking. This applies to every place I go. Why am I rewarding anyone for doing their job and often not even that. I know that many rely on tips to make a living wage and that isn’t my fault but a fault of a system that favors the company over the individual worker.