- it uses a downstream Android kernel
- it does not use a mainline kernel
- the Android kernel creates dependencies and makes it difficult to keep up to date for more than a couple years
- their AppSuport is literally Android in a container with some proprietary parts
- their apps are scarce as they need to be built for the OS (no Flatpak or any other support for the existing mobile Linux software)
- the UI and some other components are proprietary
I believe those points make clear why I see more of a future in projects like Mobian, postmarketOS, Fedora Pocketblue.