You're talking out of both sides of your mouth here. You claim that Graphene "provides far better app compatibility and stability" because it's possible to install all the Google Play adware trash inside a sandboxed profile. But then, when people tell you swapping back and forth between profiles is a huge PITA you throw up your hands and swear "Oh well that's just a Standard Android Feature, you can't blame Graphene for that!"
Your argument boils down to "Graphene is so secure that it's like having two phones in one: one that has a cool greyscale theme but doesn't do anything, and a sandboxed Google phone with all your apps, Google Play services, and personal data on it."
It is completely the user's choice to put sandboxed google play in a private space or secondary user profile. It is completely the user's choice to put sandboxed google play services in the owner profile and not use multiple profiles at all. It is completely the user's choice to source apps from outside Google Play.
I feel like we're talking in circles here: your "far better app compatibility" is a phone useful for nothing, and if the user chooses to install Google Play then they have a usable phone at the cost of their privacy. ¯\_(ツ)_/¯
The goal of /e/OS is to provide a more-private degoogled OS that is usable out of the box by normal people: an app store, maps, etc.
This whole conversation reminds me of talking to Slackware users in the early 2000s: "I don't understand what you mean, it's compatible with everything you just have to recompile it. It's 100% secure, it comes with zero services running."
Your argument boils down to "Graphene is so secure that it's like having two phones in one: one that has a cool greyscale theme but doesn't do anything, and a sandboxed Google phone with all your apps, Google Play services, and personal data on it."