Even people who do things wo getting something in return do it for the satisfaction it gives to them, so if you look it that way, there is no real altruism everyone do things to get something at exchange even it being not monetary.
I'm not totally sure I barely use Google Messages except for verification codes, I prefer to uninstall it preventing it from having any access to my local end to end encrypted keys for other apps. but it's up to you I guess.
The other one is Android System Key Verifier, for that I'm not totally sure it's malware but as it have access to your end to end encrypted keys and the way it's secretly installed seems shady to me. Looks like a way for Google to intercept end to end encrypted messages for me.
Client side scanning, it's already happening in android running google services there are two apps automatically installed which at least I know scan photos in the device. One is android system saftycore and the other I can't remember the name.
Even people who do things wo getting something in return do it for the satisfaction it gives to them, so if you look it that way, there is no real altruism everyone do things to get something at exchange even it being not monetary.