I'll use the stock calculator, phone, and files manager as long as they are secure. The messaging app is the worst so I make an exception.
Discussion
Nothing that is unmaintained is ever secure.
AOSP maintain their apps in regards to security issues or bugs.
Even Messages, which they say isn't actively supported and may be removed:
https://android.googlesource.com/platform/packages/apps/Messaging/+log
The features, however, are lacking - they mainly serve as reference implementations with just the core features. This is a big reason why GrapheneOS maintains forks or replaces the apps entirely (like the Camera). It would be best to replace more in the future.
anyshit downloaded from googleplay is SPYWARE risk