+1 for signal but i doubt whatsapp is ahead at all

Can it be used without a smartphone, like in an Android VM?

Don't forget that AppOps is not really standardized, and even the app admits that some phone's system does not implement a restriction properly (or at all).

That being said, it's very good to have, but you have to keep this in mind.
AFAIK lineage os has a more complete implementation.

To answer the question: GrapheneOS and a separate profile would be the safest

I appreciate the suggestion, but maybe I should add that I'd like to not have to change up my phone too much. It's a Fairphone 4 running the OEM Android and my preference would be to keep it that way. Are separate profiles like that a thing on stock Android?

If you are both outside of china there really is zero reason (other than preference) to use that piece of spyware.

She travels back to China sometimes, uses it to contact friends and family back home, and uses it to chat with lots of mainlanders here in Canada. For her it's not weird at all.

In fact, she expressed to me that she's perfectly comfortable with the fact that they use WeChat combined facial recognition technology in China for payment processing. When you get on public transit, you can have them scan your face and it will automatically charge you the bus fare. It really skeeves me out, but it's simply not the hill I want to die on in this relationship. I'm crazy about her in so many ways, it's okay with me if we don't see eye-to-eye on digital privacy.

And, let's be fair, for most people the real loss from this level of compromised privacy/security is far less than the real gain from helping your relationship.

Sometimes I look at products I use from dubious companies, take a step back, and think, this company is actually a blessing in my life even if there is a smaller curse attached. That said, I'm grateful for all the tremendous effort put in by many people to make the digital (and rest of) world a safer, more private, fairer and more honest place. And I try to do at least a little of my share!

If they are actually totally unwilling to use an other messaging app that has fewer of said negatives, is the partner really interested in that relationship?

I mean, just look at the arguments.
Form OP's side, it's privacy, respect of the user by the service, human freedoms basically.
From the partners side, as I understand, it is pure convenience.
Please reread my first paragraph after reading this second one. It will now hopefully make sense, if it didn't at first.

But to be honest maybe I'm not qualified for this question or something because I have a different attitude to this problem.
To me it's not my primary purpose to find a partner, and everything else is secondary.
To me, getting to know that someone is neck deep in mass surveillance tech and is so comfortable with it that they are inseparable, instantly turns me off. I don't want to live with someone who is perfectly fine with the state messaging app constantly scanning my face with an app on my phone, because that means that our values are clearly very different.

Ah, that's interesting and makes sense. So I guess your best option (if you must use WeChat) is to use the international version of the app with as many permissions disabled as possible.

Or maybe look at the Matrix WeChat bridge? https://matrix.org/ecosystem/bridges/wechat/

That's a great point, thanks! I will definitely be using the international one. I expect since I'm getting it through Google Play it'll be constrained based on the OS permissions I give it. And I don't intend to give it any permissions

Maybe get a girlfriend that isn't a brain washed spy? \s

Listen here, I like my qt tankie sleeper cell gf. As long as she doesn't hear anyone say the activation phrase, she's very sweet.

For real though, this app is pretty culturally ingrained over there and so I don't really have the option of pushing something else (we all know how real messaging app fatigue has gotten these days). Especially when other apps will be restricted whenever she travels home, and we want something that can serve as a backup when other communication methods aren't an option. I'm pretty sure WeChat will work through The Great Firewall, so it's ideal for our purposes. I have no idea if the same can be said for WhatsApp or Signal.

She's not very tech savvy at all. It would be asking a lot. I'd rather stick to something she is comfortable with.