Noobnoob I've watched a lot of articles, forums, videos, etc. A lot people said that F-Droid and Aurora store are the best app stores in GrapheneOS, which are better for privacy.
It would seem that you're getting information about GrapheneOS from bad sources misleading people about it. Suggest finding better places to read articles/forums and watch videos with factual technical accuracy.
But in my opinion, apps in F-Droid are actually not commonly used, and we can literaly install apps directly from sandbox Play Store, which seems to be safer than Aurora Store. Cause when you use Aurora Store, you are not only trusting Google, but you have to trust Aurora itself. What do you guys think about my words? I'm gald to hear.
Aurora Store still requires an account but fetches shared account credentials from Aurora Store's service by default. There's lots of information on the forum that you are more than welcome to search for on this matter.
See https://privsec.dev/posts/android/android-tips/#where-to-get-your-applications
As for F-Droid, see https://privsec.dev/posts/android/f-droid-security-issues/
By the way, for ordinary people, the degoogle part that GrapheneOS gives to us is enough in my perspective.
'Degoogle' is a misleading term.
GrapheneOS is based on the Android Open Source Project which doesn't contain the usual Google apps and services. We don't refer to GrapheneOS as 'degoogled' because that's not really the purpose and AOSP already mostly is nor how we present it. See https://grapheneos.org/#never-google-services
We can have good feature from custom ROM and Google at the same time.
GrapheneOS is an operating system, a production quality OS and not a ROM!
'Custom ROM' is not accurate terminology for an AOSP-based operating system. It's best to use the term alternate / aftermarket OS rather than custom ROM which is technically inaccurate. We avoid using the term ROM to refer to the OS.
Last but not least, which app stores that GrapheneOS officially recommended?
Accrescent from our App Store and then install apps from there. We also recommend app developers publish their apps in Accrescent if they care about privacy and security. It's generally best to use builds from developers since you're going to be trusting them anyway. App stores including F-Droid and the Play Store do not avoid trusting app developers, but they add another trusted party. Accrescent only has developer signed builds signed by devs.