… WhatsApp is the main messenger globally and it is the 'odd' people that use iMessage (and Signal, Telegram, etc.)
Statistically, sure, but it's not evenly distributed across regions and cultures. People can find themselves in social circles where iMessage is the norm and be pressured into using it because others are unwilling to install a second messaging app.
Hard to imagine any "region or culture" where iMessage is the norm outside a section of the US middle class.
Speak for yourself
Ok! I don't use iMessage because people I want to talk to are happy to install a new app to do so. :)