A scrollbar is not only a control, it's also an indicator. It shows where your viewport is relative to the bigger view, e.g. a long list. Hiding scrollbars, like some [redacted] GUIs like macOS do, is just acutely impolite, much like making buttons indistinguishable from text, or putting light grey text on a light grey background.
A solution exists, and is nearly universally implemented: scroll wheels on a mouse, and scroll gestures on a trackpad. Very, very rarely do I find a view which can be scrolled by scrollbars, but cannot be scrolled by the standard trackpad gesture, or by a mouse wheel. (BTW my mouse also allows horizontal scrolling using the wheel; so do trackpoint controls, too.)
Such scrolling does not require the pointer to even be at a scrollbar; the pointer just need to hover over the desired view / control / widget. This is really easy to achieve with imprecise input devices, unsteady hands, and poor vision.
But with this natural, easy way of scrolling one starts to really miss scrollbars in their indicator role.
(Regarding minimaps: sometimes they are helpful, sometimes not so much. I in particular find them unhelpful and bulky for text editing, but of course I'm all in favor of having them as an option for those who enjoy them.)