The problem is the lack of structure.

I organize a lot of workshops involving people from experts to executives, where always need an introduction round, and I always give them a structure to follow. Makes the task it easier, but it’ll also be much more useful for the group, as we’ll focus in the aspects of a person that matter for the context of the workshop.

For a class intro in primary school, it could be:

• name and age
• nickname you’d like others to call you
• favorite subject
• favorite hobby / free time activity

I just made this up, but a teacher could probably come up with something even more fitting.

The point is, always give people structure or guidance, you’ll get much more out of similar introduction rounds.