It means your in a large room with a lot of people talking to each other. It's not a fine dining experience where people whisper. It's a social place. The social aspect was taken out of the experience, which is vital to development. The "loud" (meaning, it's not quiet) aspect is not a negative. It's not a "lunch break" for adults to go decompress from the stress at work. If kids want quiet for studying, they can hit their school library, or other places for solitude and tranquility. It's about younger people actually communicating and discussing what is going on in the day, their life, after school, hobbies, interests, relationships, etc.. Imagine going to a playground where there are 100 children. None of them are making a sound. That would be a scary sign. You should hear kids laughing, screaming, crying... experiencing social engagement. People are being isolated from each other because they are becoming "addicted" to screens and short media formats. We are training our brains for instant gratification, but there is no retention or learning going on. Younger people aren't learning how to communicate directly with others. Without these engagements we hobble our development of things like empathy. How to control our emotions with others. It's damaging for all.
