The problem is it seems to be past its prime. It dropped support for mainstream phones more and more and is currenly limited to either very old handsets or rather exotic manufacturers.
The most recent Samsung S series they support is from 2014, almost six years ago. CM and LOS were also popular on the Nexus 4 and 5, these were completely dropped as well and even the successors do not have a recent Android version at this point.
All of this coupled with long delays of moving to the most recent Android version. Many phone were still on Nougat LOS, when there was already Pie.