I'm now part of the @Droidian Linux project.
Worked on this for properly working auto brightness on phones. But if merged, should be a progress on laptops too.

GitLab
power: Implement linear auto-brightness (!374) · Merge requests · GNOME / gnome-settings-daemon · GitLab
The current implementation of auto-brightness has two problems: The brightness updates are quite unstable, with the value reacting too quickly to ...