Amidst a bunch of changes One UI brought about that nobody asked for, it seems like Samsung has also been hell-bent on botching live wallpapers.
First off: why is it that live/video wallpapers that come with the (ridiculuously overpriced and gaudy af) themes from the official Theme Store can only be applied on the lock screen? The lock screen that a) is pretty much completely redundant next to AOD and b) is completely bypassed by fingerprint lock because that takes everyone straight to the home screen? It feels extremely moronic.
Second: why is it that live wallpaper settings are just not available any more? The settings that used to be right there in the wallpaper picker (I actually miss Android's menu button). Sure, if it's an actual app and has a separate shortcut in the launcher, it's lucky. If it isn't, though, as it really isn't supposed to - we're just screwed because we have no way to customise it at all.
At the end of the day, it seems like this is yet another day One UI completely botched up for no good reason.