Eli5 why does a survey need to have a minimum of 30 respondees to be statistically significant?

Question

I’m not the best when it comes to stats. But I see some surveys who publish findings based on <30 responses. And I know that these are not valid, and it has something to do with the normal distribution.

In: 0

Answer 1

30 is not representative at all.

Generally the minimum is 1000 people taken at random to be at least a bit representative