People changed their interaction after mice and trackpads started to universally include a built-in scroll wheel / scroll gesture.
In 1990, everyone scrolled up or down by clicking little buttons at the ends (or at one end) of the scrollbar, or by dragging the scrollbar up and down. By 2019, these buttons are unnecessary and have been removed, and the main purpose of the scrollbar is to passively report the position in the page. Dragging it up and down still works, but few people bother.
I did not know this, but I am apparently one of those few people who use a scrollbar to point to a location where I need to be. Either in source code, manuals, even on some vendors web pages I know the tech specs and the link to the datasheet is 2/3 of the page so I drag or click the scrollbar. In documents, or on webpage I have a mental image of where the scrollbar was when I read it, like page numbers in a book and I use it a lot. And no this is not substituted by scrolling with a mouse wheel or heaven forbid a track-pad. If I know I need to find something at 'M' I do not want to go through all the stacks starting at 'A'. Just saying we have been organizing content for a lot longer than the UX people telling us what we do not need.
Scrollbars are a tool and they should be functional: visible, properly sized and interactive. It helps if a scrollbar looks and functions the same on all our content, because it takes less mental strain to use.
It may be that you don't like scrollbars for your content. The obvious solution is to make your content fit so it does not require scrollbars. If you cannot manage that you will have to live with the fact that scrollbars are there as a functional tool and make sure it is kept functional.
In analogy: If I sell furniture you have to self assemble I can choose to design it to not require tools. If it does require tools I should make sure people can actually use those tools to assemble and not try to hide that tools should be used by pretending the thing to put nails in is not a hammer.
I have almost forgotten that it’s even an option to click and drag! On my trackpad I use two-finger scroll, and my scroll-shell mouse can handle horizontal scroll just fine.
But honestly even then it’s not common for me to run into those. I’m a keyboard user, so the thing I get persnickety over is whether or not you got your focus order right, if you steal keyboard focus senselessly, or if you made a UI that only responds to mouse clicks.
In 1990, everyone scrolled up or down by clicking little buttons at the ends (or at one end) of the scrollbar, or by dragging the scrollbar up and down. By 2019, these buttons are unnecessary and have been removed, and the main purpose of the scrollbar is to passively report the position in the page. Dragging it up and down still works, but few people bother.