Scrolling on Microsoft Edge is smoother for me. It would be good if Firefox could implement something similar to make scrolling feel much more smoother than it currently is.
I finally got scrolling in Firefox is buttery smooth and I'm super-sensitive to visual stutters. Here's how: get the add-on "Yet Another Smooth Scrolling WE". Then in Settings turn off "Use Smooth Scrolling" as the add-on is handling it. n About:Config, try setting "general.smoothScroll.msdPhysics.enabled" to True. Also try turning "Use hardware acceleration when available" on/off. Hardware acceleration can make scrolling smoothness worse on some systems depending on complex interactions between your CPU, GPU, RAM and graphics drivers.