I just read that they changed their stance, but for a long time, they were against implementing RCS and said users should be using another tool like Signal. That ignores real world scenarios where users ended up using SMS rather than RCS, which was encrypted with Google messages. Of course, there's more nuance to the discussion, but I found myself a few years ago having gone from encrypted messaging on an iPhone by default to encrypted messaging on stock Android with RCS to unencrypted messaging on GrapheneOS. I thought that was certainly less secure for myself and likely the average user.

But they did share valid concerns about their reasoning and most other aspects of the OS certainly have a great focus on security.