It was an acquihire involving a 16 year old who was doing it for fun.
Ding ding ding! We have a winner!
It's the same reason they dragged their feet supporting RCS, until regulatory pressure started mounting.
I find this incredibly hard to believe. And just because the Apple marketing department believes something is true, doesn't make it so.
Maybe I run in a weird crowd, but I've never met anyone who cares whether "text messages" are delivered over SMS or iMessage. In general most messaging I do happens over Signal, WhatsApp, Discord, or (in a few unfortunate cases) Instagram messenger.
https://www.thurrott.com/apple/248931/apple-didnt-bring-imes...
On a more serious note regarding the Hardware sales- Apple inc does not make that much profit based on "what" they sell, its "who" they are selling to.
It’s possible that the GP is unfamiliar with iMessage because they don’t live in NA. I have neither sent nor received an iMessage for several years. I use the Messages app for receiving SMS OTP codes only and pretty much nothing else.