but the cost to humanity may be greater than the benefit to the individuals.

sure, but that is a problem (if it really is a problem) of inaducate value accessment by people and governments. it's not a problem that would inherently be solved by a RBE, it is one that can be solved in both systems, mostly by people making better decisions in general.

an interface could be created where people could tell a system what they want that isn't currently available to them

that doesn't say how much people want them. IE what would prevent people from simply saying "I want everything"; how does the system determines that you want this more then that and by how much you want it more, and by how much you want it more then the other person that wants that as well or something else? it's easy to know what people want (in essence almost everything), the hard part is in determing how much they want it, the real amount of demand there is. that there is demand is clear, but not how much of it there is.

This would also motivate innovation. If there is an item that someone wants, but it can't be justified because the cost is too high, they can get with other people who want that item and devise a way of producing the item at a lower cost

they can often not "get with other people who want that item and devise a way of producing the item at a lower cost" due to not knowing how, not having an education in the field, not being enough people with suffecient skill set that it would justify them doing all that just to get access to that thing. it is an incentive sure, but not as effecient an incentive as in a market system where every "want" can be traded for every other "want"; where someone that wants item X but doesnt' know how to develop it can pay someone that doesn't want item X but wants item Y instead and thus both get what they want. without this trade system person A would be left wanting not being able to trade with person B for what they want.

gain you notoriety and social standing,

sure, again it's a motive, but not really as complete motive as a market system where all the wants and values can be traded.