Microg is a (very welcome!) band-aid for the fact that the android ecosystem is critically dependent on a proprietary piece of software called play services.
PMO is a different, libre, OS and ecosystem that doesn't have that problem to begin with since it is truly a Linux (as opposed to AOSP) and truly free (as opposed to android's "can read most code but Google holds all the cards")
There's a far larger app ecosystem for Android without Play Services than any other mobile OS. It's very odd to try to claim that it doesn't have that problem. Android is truly a Linux distribution too, and is truly free software. You can promote your preferred mobile OS without making misleading claims.