You're right, there is something called a "scrollbar", but many people don't see it because they are using macOS which for some reason hides the scrollbars by default.

Also phones/touchpads don't see scrollbars I think.

macOS does indeed show the scrollbar at all times when a input device other than a touchpad is attached.

My desktop Mac never hides the scrollbar, as it uses a normal mouse, however when I was using a Magic Trackpad the scrollbar would indeed hide unless I was actively scrolling.

Odd behavior.

There's actually a system preference that shows/hides the scrollbar.

System Preferences > General > Show scroll bars

• Automatically based on mouse or trackpad

• When scrolling

• Always (because I remember when smart phones didn't exist)

I keep mine at option 3 because I'm a dinosaur

Good info, had no clue that was a configurable option. Thanks for the knowledge!

If someone is asking for an scroll indicator, it's safe to assume that, for some reason, the native scroll affordance has been hidden from them.

Indeed - but then the person asking should better look in the systems/browser settings; this has nothing to do with the website.