Similarly, any business model can't rely on handset sales. Apple and Samsung sell them by the millions and we're talking a few hundred here.
Community ROMS such as Lineage OS supporting (per wikipedia) 165 devices suggest that there is grass-roots support for tinkering. Devise a foolproof method for device support on any handset (Halium) and solve the app gap by containerizing Android (Anbox) and the users may follow - but on their own hardware, NOT a custom device.
UBports lives on by the community, for the community - in spite of Canonical abandoning the platform.