JK Rowling is a transphobe, a bigot and a fascist.
drspod
SMS messages are not encrypted. Theoretically, this allows telecommunications providers to scan for and blacklist spam campaigns at the network level, if they make enough noise. On the other hand, messages sent via RCS or iMessage are encrypted end-to-end. Although an iMessage will route directly through an Apple server, Apple itself cannot read the content in transit. Lucid takes advantage of this by sending phishing texts via iMessage and RCS, turning this otherwise positive security feature on its head.
That's it. That's the "fault" that is being "exploited" that they mention multiple times in the lead-in to the article.
I personally know of two different banks who send a notification to your phone app to verify that it's you they are speaking with on the phone, and they will do this even when it's them that called you and not the other way around.
It's security theater as it doesn't prove anything to either party (as it's trivial for scammers to have a man-in-the-middle) but they still do it.
JK Rowling is a transphobe, a bigot, and a fascist.