Some diligent LineageOS projects are known to incorporate some open source kernel fixes sometimes, or grab newer blobs from other phones from other devices. But there’s only so much to they can do. In general, it’s true to say that older devices with community Android support are not completely up to date - the kernels are old, and vendor drivers are not getting updated. Outside of making big usability concessions in projects like Replicant, the community can’t do much here.
