It can be quite diverse in other factors besides the religion. e.g. mixing of race, class, politics, culture, ect

The Catholic church is racially and socioeconomically quite diverse, and produces the highest rate of interracial marriages of any religious group, and even slightly edges out atheists.

It's as diverse as any company or organization championing diversity, because obviously anyone part of one particular movement / entity is not diverse in one axis of their life (institutional allegiance)

The youth clubs were not socioeconomically diverse, where I have seen them. Nor politically or culturally diverse.

In here, they are also as racist as everyone else conservative, but also we are fairly homogenous.

> Are you saying that a group where everyone has to be a catholic is somehow diverse?

You've clearly never lived in an area with high density of a specific religious group. At a certain threshold, yes, there can be more diversity in a single religious congregation than is present in most local environments short of the local public school.

If most of your neighbors are Catholic, then you'll often just show up for the Catholic events regardless of whether you deeply believe it because that's where the community is. That's essentially what OP said about their own experience—listening to the catechism was just the tax to pay for the community event.

I actually did. The people who went to these centers were definitely not diverse in any sense of the word.

And the range of accepted ideas or opinions, political or cultural, was remarkably small. Kids who went to these centers were very alike. That is why it felt so good to them .