It's pushed because Apple is seen as less privacy intrusive.
For example, https://www.theverge.com/2021/4/27/22406303/imessage-android...
> In the absence of a strategy to become the primary messaging service for [the] bulk of cell phone users, I am concerned [that] iMessage on Android would simply serve to remove an obstacle to iPhone families giving their kids Android phones.
Or, you know, maybe, just maybe, people actually, genuinely enjoy using these devices.