Scroll bars universally suck nowadays. Maybe my "mouse accuracy" isn't what it used to be - since giving up first person shooters 16 years ago - but I shouldn't need railgun accuracy to hit a fucking scroll bar 99% of the time. Why are they a single pixel wide these days, it's not like screen-width is expensive real-estate these days, is this Apple/Ive design principles gone mad? And then there's the page resizing when the scroll bar appears that makes it look as if the whole screen has refreshed, and then it re-refreshes without the scroll-bar in the intervening time that I paused my actions wondering why the screen refreshed in the first place.
/end old man rant.
I'm looking at you Teams, Discord and maybe Slack?
Turns out MS Windows has one, too, since Windows 10. Here you press the Windows Logo Key + v.
P.S: Last sentence probably violates HN guidelines and is just rude and unnecessary if you want to prove a point.
With that said - most modern applications are webapps for good reasons. Making native apps sucks for a lot of reasons - including all the random OS-specific behavior you have to work around, specific versions of native OS libraries, etc.
Building for the web browser means, without any extra effort, you app works on all operating systems, and it works exactly the same. That's a pretty good sell to anyone trying to make a modern application that's mostly just a front-end UI for an API...
For example this page has action buttons and community links with a video on the first page, a written blurb about system configuration on the second page, screenshots/visual showcase on the third page, etc.
Personally I'm on the fence. I think it probably more often than not tends to be annoying, like most overrides of default conventions, and feels more like you're being force-fed marketing instead of reading information. This specific page would probably work just as well if they kept the sections, dividers, and even the animations, but just let you scroll naturally.
But then, maybe it gets them more downloads or something.
But yes, the downside is that some people think that websites, that really just should be pages, get gamified and abused like this.
After reading the hint here, and trying it out, my back stack is polluted a lot.
Edit: I went back... not they don't even recognize small scroll ticks, they just ignore them... :) You have to violently scroll to progress.