Downs-Thomson paradox is an old problem that people used to talk about a long time ago. It's about how two different groups of people feel differently when it comes to the size of a group. group size can affect how people feel, think, and act. For example, if there are too many people in a group, it can be hard for everyone to stay organized and get things done. But if there are too few people in a group, it can also be hard to come up with good ideas and find the right people with the right skills.
The Downs-Thomson paradox says that people usually like big groups — but if a big group gets too big, people start to dislike it. This means that if the group is too big, people become less happy with it, even though the size of the group was what made them like it in the first place. This paradox is still talked about today because it helps explain why people don't always like big groups or organizations, like companies or governments.