Discord's notifications at least have that View button, but clicking on it still has the notification pop-up remain on the screen. You'd think that taking actions with the notification's buttons means it's been acknowledged and in many cases those buttons lead to a more elaborate view of the information that is in the pop-up. I suggest making interacting with the notification also close it. Also maybe a setting for the display time of notifications; it seems a tad long for my liking currently.
This seems to be a problem in discords handling of the notification. In general this works, e.g. try this: notify-send --action=Press test Clicking on the button closes the notification. It's the application, which pushes the notification, which also tells me to close it again.
Hmm, after further thinking, I feel like this could be because I've installed Discord as a Flatpak. It's probably messed up some inter-process communication pipeline or another.