It can still be a lot more efficient to grab the scrollbar to jump to a section of a large document. For example, you can instantly get to say 3/4 of the way through by moving the scroll bar a very short distance, which when done with the scroll wheel or trackpad gestures could take a very long time.
The scroll bar is also sometimes a nice visual cue to the size of a document you've just opened for the first time, again something the wheel/gestures don't necessarily inform.
I have permanent scroll bars enabled in macOS too.
It is pretty much required if your primary interaction with the computer is through a drawing tablet. My Wacom has a touch-sensitive wheel on it but it's usually a lot more natural to just poke at the scroll bar with the stylus.
I loathe the modern trend towards hiding all scroll bars everywhere because of this.
Looking at this very page! Using the middle mouse button takes me 3 or 4 seconds to move somewhere close to the bottom of the page, much faster and less frustrating to grab and drag the scroll bar. Is there some easier method I'm missing?