Others have explained it (places where social interaction is the primary intent - not home and not work) but I’ll add - old European cities (and most smaller towns) have some sort of public square. Many have lasted to this day and are still used. We can still build them, we but our chosen form of urbanization isn’t that conducive to it so we don’t. In North America in the 80 and into the 90s, malls we’re 3rd place. Then they started aggressively going after loitering in malls since simply sitting in a mall doesn’t produce economic activity. Many malls died and many are still dying. Those that survived achieved the - nobody goes there to chill anymore. Just to buy what they need, maybe eat, and then leave. Nobody plans to “meet at the mall” anymore.