LineageOS is no longer the CyanogenMod it once was. Where CM received regular updates and supported a plethora of devices, LOS has been dropping devices and doesn't do Oreo. My Galaxy S7 is no longer supported by LOS for absolutely no valid reason: https://lineageos.org/Changelog-18/
> Removed 14.1 devices
> Samsung Galaxy S7 (herolte) and S7 Edge (hero2lte) due to licensing issues of the device trees
As for why the device was dropped, go ask the maintainer. They're probably volunteers and it might be that one of them just stopped having time to do that. I don't think they're actually paid for porting LOS.
Somehow this sort of thing never happened to a recent device like the S7 back in the days of CM, before it became Cyanogen Inc. Between the death of Cyanogen Inc. and the birth of LOS a crucial ingredient appears to have been lost, leaving the project as a whole less vital that it was before.
Overall interest in the ROM and android modding community has been decreasing. CM appeared right when android really started gaining traction and the modding community prospered. That was when phones were seen as the cool new tech with all these interesting features. Nowadays most people don't care what is in their phones as long as it runs the apps they want, takes decent pictures, and lasts for a decent part of the day. It also doesn't help that nowadays app developers have started intentionally crippling apps when a custom ROM is detected.
Because of this most people don't contribute to android ROM projects anymore. For a lot of people it just isn't worth the effort those that do care tend to keep up with new tech and buy the latest and greatest tech so they aren't maintaining old devices as much anymore unless they were major hits or a personal preference of the maintainer.
As for why a lot of features have disappeared, through the whole process of surviving the Cyanogen Inc. issues, it took everything the community had to keep basic android supported let alone all the extra features considering how many devices they support. Now that Treble has been deployed, this shouldn't be so much of an issue but maintaining so many old devices that have long been deprecated isn't easy.
Also, as for why the S7 is no longer maintained, apparently there was some bs issue with the software license on the S7 binaries.
neither of them do updates for the same reason. Yeah, you might get a few updates for a few phones, but that is because the OEM did the work too.
Every off-brand android distro does the same thing: they get the kernel+drivers from the OEM image, and repackage the rest (the rest being AOSP).
besides the android libraries, nothing is visible. It is all a binary blob picked from the OEM image. So if the android version X is release by OEM, the off-brand android distros will pick up version X for that phone by just building AOSP on top of that kernel+drivers. When a new version for android comes up and it depends on a newer kernel version, that phone won't be updated no matter what! ...exception is if the phone's kernel+drivers are shared with another model that did received the update, but you guess how rare that is.
bottom line, no matter how may hours an off-brand android distro use, it will NEVER support anything newer than what is supported by the OEM.
In some cases, even if they claim they are releasing android security patch X for your phone, if that patch bundle included kernel fixes, you can be guaranteed that they will not be included.
> Removed 14.1 devices > Samsung Galaxy S7 (herolte) and S7 Edge (hero2lte) due to licensing issues of the device trees