>We should focus our efforts on truly open platforms.

De-Googled Android was/is a truly open platform. Same result. You're pointing out maintenance issues.

How many developers do we have to maintain this or any other platform without pay? That problem applies to a de-Googled fork of Android, or a complete bottom up build of a new platform.

The benefit of using an Android fork is the labor savings on what's already built.

Maintenance is not going away just because we build a new OS.