Writing a chorus people can shout

A genuinely shoutable chorus tends to favour short, punchy phrases over long, winding ones, since a crowd needs to catch and confidently repeat the words almost instantly rather than having to puzzle them out carefully line by line while the song is still actively playing in front of them.

Rhythmic clarity matters every bit as much as the actual words themselves here, and a melody that lands squarely on strong, clearly emphasised beats is considerably easier for an entire room full of people to join together on, even without much prior rehearsal or any real familiarity with the song beforehand.

Simplicity, once again, does the heaviest lifting in this particular case, and the choruses most often shouted back enthusiastically at live shows are rarely the most lyrically complex ones available, they are instead simply the ones that ask the very least effort of a completely first time listener in the crowd.