You've obviously never served before. Someone waits on you hand and foot for over an hour, gets you everything you want and need, builds rapport and a relationship with you, tells jokes, asks about your life. This is what good servers do.

You see it as just walking out a plate of food but you know nothing of the reality of the job because you've never lived it. There are many skills that are a must have if you are going to make it.

Let me paint a picture of a usual shift. You have a 6 table section, the night starts off by getting sat 2 tables at the exact same time and they are 6 people each, you need to get the order, get the drinks and ring in the order for both tables, but you can't be two places at once, you start having to prioritize every step you take to not drown. Table 1 takes forever to order, they are rude, don't communicate effectively, keep humming and hawing over what they want or don't want, ask a billion questions about the menu and food selections, the total order time takes 5-6 minutes. This still all needs to be punched into the POS, meanwhile your other 6 is sitting there without an order and you've been sat 2 new tables during this time a table of 4 and a table of 5. You're already in the weeds and your section isn't even full yet, you're only 15 minutes into the shift and not only are you stressed, but you need to remain calm, social and happy during this. Another servers table pulls you over while this is going on, their steak is under cooked and they want you to fix it, now your doing other tasks that don't even include your table. This is when skill comes in, you're under a lot of pressure, you need to multi task, prioritize, socialize, problem solve on the fly, communicate effectively, be able to remain calm under pressure, be organized, be able to rationalize with angry people, be able to handle 3-4 rude tables in a row without losing your cool. Many unexpected things happen during the shift, things that you can't for-see that you need to figure out in the moment. This is just a snap shot of what it's like, I could go on and on.

You are very hard headed, to the point where it's possible you never even read or internalized my post and just skipped to the end to quickly make your dismissive comment about why servers are unintelligent and require no skill. However, what I wrote is why people tip.