Encelados Aurora Store isn't recommended because it might violate Google's TOS
The main reason it's not recommended is because it's insecure. It lacks some of the protections I've explained to you. Some people use Aurora Store to install or update apps from the Play Store more conveniently when the Play Store blocks them from installing/updating them.
Encelados Obtainium isn't recommended either as it is untrustworthy according to @Watermelon
And potentially insecure due to being bloated, and undoubtedly less secure than Vanadium.
Encelados Which leaves us with GOS-built-in Accrescent or using original built-in / sandboxed Google Play Store services.
I think downloading APK files can be a legitimate way to download apps too, as long as you only download from the official website of the app, and only if it isn't available in a secure app store.
Encelados Accrescent is for FOSS apps only
No. Accrescent is itself open source, but it aims to be inclusive to both open source and proprietary apps. It aims to be a more secure alternative to Google Play Store, so it has to fulfill the same purpose.
Encelados Especially when it comes to banking apps such as PayPal and such (which happen to all run for me on GOS. I seem to be lucky here)
I've recently seen posts from the GrapheneOS team saying that only about 10% of banking apps don't work on GrapheneOS, so you're not lucky, you're just not unlucky :)
Encelados However, @fernlike says it's OK to use Obtainium in combination with app veryfier.
If you verify the authenticity of an app (by using AppVerifier, which isn't magic because you still need to have AppVerifier compare the app you select against the authentic fingerprint), and ignoring the possibility of an attacker stealing the signing keys from the app developer to create a malicious but properly signed version, you can download apps from anywhere, not just Obtainium. If you want to try and prevent the possibility of an attacker delivering you a malicious but properly signed version of an app, you need to install and update it from a secure app store.
Encelados is there a way to use GOS normally like any other phone while at the same time completely avoiding any Google services, especially Play Store? From what I've learned so far, it doesn't seem like it. If I want access to all the apps, like I've had before on other phones, there seems to be no way around using Google Play Store?
You don't have to install apps from Google Play Store. But if an app is only available on Google Play Store, then there isn't much you can do to install it while avoiding the Play Store, and it's not something specific to GrapheneOS or something that GrapheneOS can solve.