On that note Samsung are replacing their application with Google Messages.
https://9to5google.com/2022/02/14/google-messages-samsung-galaxy-s22-us/
and they have a help guide on it:
In this specific case it’s either a case of open source and no E2EE which equals no privacy, or Google’s Messages /w RCS and E2EE for users which also have it, so there is some privacy there.
Open source SMS applications give no privacy on a network where the carrier sees and can do anything with your messages anyway.