At the end of 2016, the CyanogenMod project was declared dead, but the core team of CyanogenMod's father Steve Kondik was still retained. They then launched the LineageOS project. In January 2017, the LineageOS website officially went live, to a certain extent the CM The continuation.
However, the current number of ROMs in LineageOS (about 90 devices now) can be shame compared to the current year's CM, but developers are working hard to keep all LineageOS supported phones in sync over time , The current stable version is 14.1 (based on Android 7.1.2), and developers are actively adapting Android 8.0 / 8.1.
On February 4, LineageOS announced the suspension of support for the Asus ZenFone 2, with the addition of the Sony Xperia Z5, Samsung Galaxy S6 SM-G920F, Samsung Galaxy S5 Sport SM-G860P, ZTE Axon 7 Mini and Red Rice 3S / 3X Model support (updated to 14.1).
As you can see, the LineageOS project supports older devices one or two years ago, as fewer and fewer third-party ROM users are sought after as official ROMs become more sophisticated.
And for these phones a year or two ago, most officially stopped upgrading and maintaining them, and LineageOS could help them upgrade to the latest software, the latest security patches, to extend the useful life of these devices.