Do you believe there is a reason for every little thing that happens?

On Friday, I was asked, why in Islam for certain events, men and women were segregated.

I've grown up used to the idea that segregation existed in Islamic events. So it's kind of become the norm.

But what's the reason for the segregation? Or is the answer the obvious?

Principles are that we shouldn't look at the other sex in that way. So if segregation didn't exist, surely it would be a test of our faith?

Also, daily life involves mixing. Then for a 2 hour Islamic event, you get segregation? Is it pointless?