I think the majority of people can agree that wandering traders are generally useless in terms of their trades - Usually overly expensive in emeralds to get a decent amount of blocks or items from them, and that's if they even have something useful. Typically they are also quite rare, even more so when many people are online. So... why not make them potentially have better trades, or even more custom ones. For example trades for certain spawners (probably not overly OP ones), relics/dust, custom enchants- or the like ball forms of them before they are opened. I don't know, just generally cool and USEFUL items that would make good trades. Doesn't have to be for emeralds either, that would be too easy.