>The problem is that modern UI's can do so much that some has to be hidden so the common use cases can be easier

Bollocks. The "modern UI" can't do anything that much more that Windows 95 wasn't doing already. Too bad the touchscreen became standard long after anyone cared about good UX, and so the UI paradigms are still struggling with this new kind of hardware.

There is no reason ever to hide the scrollbar, which is not only a control, but also an indicator.

The UI designers don't hide it for the sake of good UX, it's for the sake of being "brave" - leading to articles like this.

I was just thinking about this the other day. OS X, in its earlier days, as a marvel of usability. Every last thing was seemingly crafted with utmost attention to ergonomics (e.g. the omnipresent menu bar is on the edge of the screen so it's easier to hit with the cursor), consistency, and intuitive discoverability. Again, the menu bar is a good example of this: it's always there, actions are laid out in a way that you can browse them to look for functions, and each item has the associated keyboard shortcut shown. The old HIG document was pretty well thought out.

iOS, on the other hand, is a byzantine mess of nondiscoverable gestures, meaningless hieroglyphic buttons that you have to blindly press to see what they're supposed to do, and general UI antipatterns. This isn't the only post on HN today about modern UIs, prompted by phonisms, regressing functionality. There's one about scrollbars too, which is another area that Apple has lead the charge on messing up.

I mean, I'm personally strongly against showing scrollbars almost everywhere on mobile because any kind of visual noise makes the UI harder for me to parse, the scroll position is not relevant to me usually, and there is not enough screen real estate to make it an actual usable control. I understand this is a personal preference, but I assure you I am not alone and these ideas _were_ tested and debated because there aren't obvious solutions here. You have a much much bigger pointer closer to your face than on Windows 95 (which I remember as a usability nightmare personally to me as a child, I don't know if people have rose colored glasses or it is a generational thing). On desktop I don't have any good arguments, but at least it is an option to re-enable there.

This is the first and only time I've heard someone argue against scrollbars.

Even the very thin and translucent ones that just function as an indicator?

I find the ones that are translucent and appear on touch to be very useful. This is mainly seen in the MacOS world I think, I know for sure I see it in VSCode.