Yes, even when using apps that track you, there is still a benefit to GrapheneOS because you can control exactly what apps get access to and google play services no longer has access to the vast amount of data it does in most phones.
Any app can track you, but if all permissions except network are disabled then the only thing the app can track is what you do in that app. If you use different profiles to isolate "bad" apps then you can also completely prevent any tracking when not in use by ending that profile's session.