They have done it as a rare one-off. Years ago one of the free crown crates gave me a spider pet, and I contacted customer support, explained that I'm archnophobic and hated even having it in the menu and they deleted it for me. (I did not ask for, or receive, any compensation - I didn't care about losing out on a crate drop, I just wanted the spider gone.) Thankfully I haven't needed to ask again but I doubt they'd be willing to do that on a regular basis because I assume someone had to go into my account data and remove it manually.

So I can definitely see the appeal of this system for players, but I think it could have significant downsides as well. What about one-time rewards within the game, like costumes or skins from achievements? If you delete them there's no way to get them back. Should this system only work with things you can buy again if you change your mind?

IMO a better system would be the ability to mark collectibles as favourites so they're always at the top of the list. There's an addon which does this on PC and it quickly became one of my favourites. It makes it so much easier to find the things I like using.

Maybe an official version could take it further and also have an option to hide things so they're removed from the list entirely, but there's a menu that will allow you to unhide things if you change your mind.

I would like either a hide option, or a favorite's option, for collectable cosmetics and even houses in those respective tabs.

Its annoying not being able to put the houses into categories based on wether I've decorated them or not.

Its annoying to have to scroll through hundreds of items to find my favorite costume. Let me favorite them already.

I'd prefer a character favorite option. I regularly forget which costumes look good on which character.