Are you saying because Graphene is unrootable and 150k choose it means user space is fine?

Because those 150k made a choice to switch to a custom rom with the features built-in that they would typically need root for on ANY stock OEM rom, such as effective system-wide Adblocking

Ofc userspace is just fine in that scenario

Now, if you're saying only 150k people choose to flash a custom rom out of billions of Android devices that userspace is just fine and dandy, that's just misleading. An absolute ton of those billions of devices are most likely Samshits, which is actively hostile to user choice and rooting and does everything they can to stop it. Up to and including (like someone else commented here) using Knox to brick the phone.

Living with userspace because you can't or don't want to overcome your choosen OEMs blockers/hostility is NOT evidence that user space is just fine.