My laptop has problems with brightness control, as in brightness doesn't change with brightness keys automatically detected during install. I have yet to find why exactly this happens, but I have a stopgap in the form of "xbacklight".
xbacklight is a RandR based backlight control application, included by default in Solus stable repos. It works perfectly for changing backlight through CLI, and more efficiently through custom keyboard shortcuts.
However, backlight functionality was moved into kernel's ACPI interface, making this slightly unnecessary. Also, Because it goes through RandR, it is dependent on X.
acpilight acts as drop in replacement for xbacklight command, while acting directly through kernel's ACPI interface, making it workable even without X. This shall come in handy with eventual shift to wayland (we all know its a when rather than if).
I have no idea how many people will be using this, but my Acer 5755-9401 has had this issue with every single distro including Ubuntu/Mint, Fedora, Arch/Antergos and Solus.
Here is the homepage for acpilight, where further information can be found, along with source code: