The benefits for overcrowding that I can think of off the top of my head are twofold.
First, overcrowding enables sub-optimal choices to be successful in a market where there are better alternatives and enables those better alternatives to increase their profit margin or become more selective. What do I mean by that? Overcrowding causes scarcity. This scarcity causes people to adjust their cost benefit equation and make choices they would not make given the crowding. Using the food court example, it enables lower quality restaurants to thrive since a subset of the population will rationalize that the decrease in quality is worth the decrease in wait time. The nicer establishments in the food court can also price out people, increasing their profit margins and becoming more selective in their clientele, because more people want to visit them due to their quality or because the number of people capable of meeting their cost increases even though the ratio within the population is unchanged.
Secondly, overcrowding encourages efficiency. In order to maximize profits, businesses need to better figure out how to serve their clients in the best way possible while maintaining a place people want to come to. You see some of this mindset in Lean and Six Sigma.
Now if the question is what are the immediate positives for consumers, the answer changes. There aren't really any outside of the potential for increased social interaction.