iOS/iPhones are the majority of phones in Canada and the US (~60%). However, if you take the upper half of household incomes that number skyrockets to 80-90%. Comparatively, in the UK it's 50/50. In the rest of europe android mostly has a 60-75% market share (tends to drift more towards android the more eastern you go - signalling wealth has a lot to do with it).

The reasons why are varied (everything from wealth signalling to switching being a pain and iphone mostly had a first mover advantage for quality and availability for the first several years), but it's only in the last two years that I've seen people start to use multi-platform chat apps here. Most of my peer group with other parents all default to imessage group chats for sharing photos, stories of our kids.

I am also starting to notice a loosening on apple's services. Spotify is used by more people than Apple music even amungst the apple households I know.