Given that iCloud backups don't contain Signal messages, and "ask you for a copy" and "exploit the OS" affect any application... can you clarify?

The context was what are things that those with more or less unlimited resources can do in order to read your signal messages.

They are 3 particular paths that aren’t in any way open to most attackers but will work here.

Saying it impacts all applications isn’t wrong but it’s also not relevant to what was asked.

If whatever the hell you are doing requires a threat model where the NSA is interested in finding out who you are talking with and what you are saying the original comment of signal is inappropriate is 100% accurate.

If your threat model involves NSA finding out who is talking to you, PGP literally doesn't help you at all: it doesn't protect metadata.

Just to be clear I’m not advocating for PGP at almost any point in time, especially not in 2024.

Ok, sure! Just: this is a thread about why WhatsApp and Signal are so much more successful than PGP, and the argument given was that they sacrificed security to get their popularity. No, that's not it.