To the former, there are many occurrences of societies without tipping (Korea?), although this is shifting as western influence progresses.
To the latter, let's look at this as a commons problem: The more people who tip, the less business owners think they need to provide as base salary, eventually tipping becomes assumed to maintain a minimum standard of living as it has for most minimum wage American service jobs. It distorts incentives and muddies the water around providing meaningful minimum wage guidelines.
On top of that it provides a negative customer experience. I have the money to tip. But I'd like not to turn making simple purchases into a "how much do I have to give extra to not have people look at me odd?", a game of "how can I drop this in the tip jar so that they SAW me drop it in" and other really... fake social tendencies that I'm not happy with myself for exhibiting, but I can understand the need for. If I knew I could go somewhere that might have slightly higher base rates, but both treated their employees at a better level AND spared me the social/mental cost of the tipping ecosystem, I'd let my money speak for itself.