Convergent Encryption and Why No One Uses It (2020)

I submitted this in light of the recent iCloud end to end encryption announcement which seems to indicate they're using Convergent Encryption here:

https://support.apple.com/en-ca/guide/security/sec973254c5f/...

I know this is meta, so off-topic, but I keep using the upvote as a "too long to read right now" button.

Is there a better way to do this?