That would be the least of my worries as SMS is completely unencrypted, but Google can do whatever they want on most devices as Google Play services is a privileged app, they're not exfiltrating your text messages though.
Discussion
Apple has plaintext cloud backups for Messages app (SMS/MMS & iMessage) so they have access to your texts sent to iPhone users, along with the carriers.
If you're not using an alternative Android OS then Google Messages is actually the best choice because you get end-to-end encrypted RCS with other Google Messages users, and possibly iPhone users in the future.
I'm just trying to find a way to communicate with the average person. I have a really hard time convincing people to join Signal. Most people just text by default
