As a tetraplegic person, sticky keys are my lifesaver. I can only push one button at a time on my keyboard. Thanks to sticky keys, I can write grammatically correct and use key combinations.
That's what sticky keys is made for. Normally, it shouldn't be active on default though, on my computers it never was. I always had to turn it on.
The shortcut to activate them is active by default and windows will display a notification when you press shift 5 times (I think) asking you about it. That happens a lot when you play some games.
Easy enough to turn off the notification though. So not sure what OP is fussing about.
For me, it's a one time annoyance each time I setup a new computer or reformat mine. I never think about it till the shortcut triggers, and then I disable it. Not world ending, but kinda annoying, and less tech savvy won't know or realize they can disable it despite it saying so in the popup. But I'd be more satisfied if the notice to turn it on would just pop into the notification bar instead of an interrupting popup that must be addressed to return to what you were doing. Sure, let us know about it, but don't pull us out of what we're doing. I in general hate any feature that interrupts your work to make you interact with it instead unless it is extremely critical, and this notification is not.
It isn't on by default, but pressing shift I think 5 times fast in a row is a shortcut not even to turn it on, but to display a pop-up asking you if you want to turn it on.
You can disable that though. However it still seems like something that shouldn't be happening by default, since no one is going to want to use it without knowing about it, and at that point opt-in seems better with how easy it is to do accidentally.
Can it not be a notification in the notification bar that doesn't demand focus? Also then full screen games suppressing notifications could do it's job.