The difference is evident: Everyone in your example is used to using a different app. In the USA, iMessage can handle texting as well so it remains the default. It allows you to converse with other iMessage users and with Android users. The default “just works” and since iPhones are very popular here, it is more common to be messaging with other iMessage users than with Android phones. So much so that messaging on iMessage and texting on iMessage are considered one and the same by iPhone users so they don’t differentiate capabilities and just blame Android users for “breaking” their messaging features.
The difference is evident: Everyone in your example is used to using a different app. In the USA, iMessage can handle texting as well so it remains the default. It allows you to converse with other iMessage users and with Android users. The default “just works” and since iPhones are very popular here, it is more common to be messaging with other iMessage users than with Android phones. So much so that messaging on iMessage and texting on iMessage are considered one and the same by iPhone users so they don’t differentiate capabilities and just blame Android users for “breaking” their messaging features.