MacOS – El Capitan sluggish mouse scrolling

I arrived at this page because I also perceived a subtle change in the trackpad scrolling mechanics after upgrading to Mavericks. It does indeed feel that medium-speed scrolling is slowed down a bit from before (10.7 in my case). I don't have a machine running the older OS to test this on, though.

Anyway, I turned up the scrolling speed to max in System Preferences > Accessibility > Mouse & Trackpad and find the new mechanics tolerable on that setting. This is maybe not the solution you are looking for but perhaps other readers will be content as I am with this fix.

Actually, this is not a thing you can fix on the operating system as technically you still are using the same window/part of a window which is a web view (in whatever browser you are using).

This can only be really fixed by the webpage itself by not making some elements scrollable. For example it's possible to deactivate scroll-zoom in some map providers widgets.

I'm sorry to say that you may not be able to switch this off on an OS Level. Depending on the web browser you are using, there might be an extension that forces to turn scrolling off for some elements but that would most likely lead to partly unusable web pages if you ever need to scroll some of these elements.