Minor nitpick, but the quality of compression for pictures/video sent over FB Messenger is atrocious compared to that of iMessage. Like, we aren't talking just technicalities, it is very visually obvious and jarring. Same when it comes to video chat, Discord and FaceTime have waaaaay better quality and reliability.

I've got ten year olds who love texting their relatives, and I'm not willing to send my kids into the Facebook meatgrinder yet.

You can be signed up for Messenger without being signed up for Facebook, I think. (Or, at least, you can deactivate a Facebook account and still use Messenger.)

Sure, but that's still Facebook.

I don't want Facebook having any level of access to under-13 minors' devices.

Does deactivating Facebook mean anything on the user side? I remember trying to delete my FB account (Which in their parlance is a different thing) some years ago and it was an oblique nightmare