https://github.com/Hummer12007/brightnessctl brightnessctl allows one to control brightness in the console. It seems included widely in distributions and there are multiple versions floating around in overlays: <https://gpo.zugaina.org/Search?search=brightnessctl>. The most promising seems to be one that has use flags for choosing between systemd and udev approaches: <https://data.gpo.zugaina.org/guru/app-misc/brightnessctl/>.
The GURU overlay is an "official" repository, you may be interested in just adding that overlay to your system.