Android is unhealthy versus its former self in that it has been increasingly hostile to developers. Your examples of /e/os and lineage are representative of the "look-but-dont-touch" nature of Android.
Not to diminish the hard work of the developers of them, as they are useful, but they do not stray far from what Google provides them for better and worse. As you say, they're alternative builds, primarily to reduce the ties to Google, but they largely adhere to the same APIs, have the same menus, have the same quirks. Perhaps graphene goes above and beyond, I have not used it. I remember Cyanogenmod having more divergence in feature set and appearance from what Google provided versus what Lineage can do for you now. I miss when Android was good, but it's just become the platform I don't want to upgrade and see what I lose next.