I am not sure why anyone would want this. There is virtually no benefit whatsoever to removing items from your library other than added liability of possibly losing owned assets forever (some people will surely click this by mistake, and then file complains to FAB support).
Hiding them serves the purpose of cleaning up your library without this risk. That “You know they’re still there” and it’s bothering you sounds like a Psychological phenomenon on your end and not a problem with how the store is programmed.
Now I’m stuck with these garbage in my library forever.
Other than satisfying some weird neuroses about cleanliness (???), is there a real reason why Epic should add a feature that poses a potential risk to customers when hiding them otherwise serves the exact same purpose without said risk?