I trust Fastmail because I pay Fastmail to provide a secure mail service.

I also have a gmail account. Google is upfront about stating they read my email through gmail. Many times I’ve seen Google use dark UI patterns to hide their tracking and snooping. E.g. location tracking on Android or the way they ignore thr Do Not Track header.

Even though they might not sell data directly, they are insistent on gathering it for their own hidden interests.

I don’t trust Google.

I wonder what distinction you draw between privacy and security.

It's the difference between bodyguards and curtains.

Hey, if the bodyguard is tall enough and stand in front of the window, he'll also serves as a curtain!

/jk

Curtains are also a form of security. Attackers can only use your information against you if they have access to it.

What’s another phrase for privacy? “Securing your data.”

non-private data is often insecure data.