In WoW, I used the AH system, unanimously better, didn't need to wait around trading pointlessly, can leave your item in and carry on, or conversely stop what you're doing very briefly to buy an item then return, without having to wait for anyone or have someone waste your time.
I don't like that ESO traders aren't server wide as spending 45m travelling about looking for something that doesn't exist is a waste of my time imo but I imagine that's a fun part of it for other people.
AH was my fave by miles.