In Firefox 70, there is a new feature called kinetic scrolling . If you scroll the web page using trackpad (or possibly touchscreen), the scroll event will not stop immediately after releasing your fingers, but it will gradually slow down, as if a rotating wheel slowly stops. After using it for a short while, I started to hate it really quickly. The problem is that the slowdown-and-stop occurs very slowly and if you just want to scroll the webpage to continue reading, you need to wait several seconds until the page fully stops moving. That’s really annoying. Fortunately, this cool new feature can be disabled. Just open
about:config page in a new tab, search for
apz.gtk.kinetic_scroll.enabled and set it to
false. Tada! No more kinetic scrolling.
 I found these related Mozilla tickets: #1213601, #1564238