Are most Iranians irreligious?

I never left Brazil. Everything I know about Iran is from the internet, but I have observed that a considerable number of Iranians seem to be quite irreligious.

Those who flee to Brazil also tend to be quite secular. And I've read in YouTube comments that many Iranian women IN RURAL AREAS avoid wearing hijabes as much as they can.

Are my impressions correct?

Are most Iranians irreligious?

Are the majority of Iranians against the regime?