Apple can still read ~100% of all iMessages in real-time because iCloud Backup (non e2ee by default) serves as a key escrow backdoor in the e2ee of iMessage. It is thus legitimate to state that iMessage is not e2ee as in practice each iMessage is also encrypted to a key held by Apple (in addition to the endpoints).
Even if you turn it (e2ee iCloud Backup) on, it's ineffective, as both parties to a conversation must have turned it on for the conversation to be private.
Even if you turn it (e2ee iCloud Backup) on, it's ineffective, as both parties to a conversation must have turned it on for the conversation to be private.
Your beliefs are inaccurate.