Yes it's very annoying not to be able to close a Notification in Big Sur easily.
- It's unintuitive as there is no visual hint where to close the notification, which takes energy to remember
- You need to hover the top right corner of a notification which takes time
- The appearing close button (X) is way too small so I need to aim which is extra friction
- I often times click next to it for it to open the relevant app (Calendar in my case) which is annoying because that takes time, and I need to close that app again.
- When I miss click or click to open the notification (banner) remains in place. Which forces you to use the small close button anyway