Yeah, it was one of those things I noticed when I first started using Linux and wondered why every other OS didn't just copy it.
On the Mac side where key combos and modifier use is more widespread among users, it’s probably because there’s no intuitive visual that can be associated with the interaction.
If you tap the island and if there's any activity there, it doesn't scroll up it switches to activity app. You need to hit the top edge of the screen not the island. And that is hit or miss, because 30% you hit the island and often there's activity there.
It was better before when it was not an island and activity was rare, only when you're navigating or on a call. Now every app and it's dog has a live activity in island.