Why Do Most Restaurants That Serve People Take So Long?

Because unlike fast food restaurants they have to cook the food after  taking your order . Most fast food places have everything pre done and can throw it in the sack and away you go with a sack of tasteless nourishing food!

I don't know about where you live, but in our small city, the restaurant owners tend to employ as few servers as they can get away with, to hold costs down (which isn't too smart, because a lot of people get tired of long waits to be served).  The last restaurant I worked for (I was in prep), employed more people in the evenings and on weekends, and most of the complaints weren't because the food wait was long, they were about the servers taking so long to take their orders, then get the food to them, then check back to see if everything was OK, and then trying to get the bill.  I think you find that a lot anymore -- businesses cut down on employees to keep their money output low, but it sure doesn't help the customer out in the long run.