Regarding Play Services for AR:
- it is a known Google Play annoyance
- you can simply allow it to install and delete it right after that
- if you make a new user profile and install Sandboxed Google Play, you will notice that it is no longer an issue as this has been tackled by a recent GrapheneOS release
I understand that in some communities it is still common to use MMS to share pictures. However, both SMS and MMS are highly insecure and outdated protocols. If you care about privacy and security of what you send and receive you should stop using SMS and MMS. In fact, in a recent attack called Pegasus, the attackers were sending text messages with a link. It was a zero click attack, a user didn't had to click on the link. Once you received that message, you were already pwned.
If you want to have proper private conversations (and group chats), be able to send and receive photos, videos, and other types of media use Signal.