There’s something called DDC/CI Display Data Channel - Wikipedia
My Dell monitor, for instance, allows me to change inputs from open source software on my Mac laptop or Windows desktop, without needing to touch controls on the screen.
Here’s and example of the software https://www.ddcutil.com/
And there’s more practical info about it here: Hands Free Monitor Input Switching for VFIO using DDC - The Passthrough POST
It does, with some caveats.
https://dough.community/search?context=category&context_id=48&q=DDC&skip_context=true
Have a read of those.
Biggest issue (for me) is that switching inputs can’t be done from a device that isn’t the active one.
Works in general at least for controlling brightness, contrast and volume. Though contrast cannot be set to values below 25 at least with ClickMonitorDDC 7.2.
Something that came to my mind, maybe someone of you can answer this.
Is it possible to change VRR (On/Off), Strobing (Off/Setting x) and integer scaling (On/Off) via DDC/CI?
For example:
I have a game (Apex) which I can play stable on 144FPS@4k, with that Game I want to turn VRR off, and activate Strobing.
For another game (COD) which I can’t play constantly on 144FPS, I want to use VRR.
For some retro-games I want to activate Integer scaling.
Could this work? 
To anyone wanting to control the monitor brightness via software on Windows, I use Twinkle Tray and it works great with all the monitors I’ve ever had.
Nice is that Twinkle Tray is free and open source. Looks like it’s solely for brightness though. And its start takes really too long for its features. Electron is probably overkill for such a small utility.