This has been an issue in OneUI for several generations now, and this is an excellent opportunity to fix it. There are many aspects of the user experience that aren't consistent, mostly in terms of look (transparency, roundness) and also functionality. I shall list them below:
1. Not all notification app icons are round. Some are round (gmail, other google apps) and some are a "Squircle". This is not consistent and is very obvious with the new rounded notifications. Switching them to match the icon shape of the home screen (or just picking one or the other) would be a vast improvement.
2. Along similar lines, the "roundness" of the Quick Panel and Notification Panel elements are not consistent, and if I am looking correctly even the different elements in the Quick Panel alone aren't consistent. They should all be the same radius. The notification popups should also keep the app icon and arrow for more details in the same place (centered in the radius of the pop-up) instead of moving them up closer to the edge
3. The notification transparency (and system transparency as a whole) is not consistent. Different areas like the app tray, folder backgrounds, folders, panel backgrounds, and notifications themselves all have different gradients and different transparency. This should be a tweakable setting or at the very least unified (they don't all have to be the same, but similar elements should be. ex: the notifications on the lock screen vs the notification panel should be the same, currently they are not)
4. App color pallettes are not applied to all apps. This should be changed. Many third party solutions have the ability to tweak apps that don't have native support for color changing, as does Apple, so Samsung should be held to the same standard.
