This is quite an important topic, because ultimately the creation and maintenance of software supporting the system is one of the larger costs to providing the system at all. As we have seen many times in the past, a lack of resources for software and hardware maintenance can end a project.
Re: Wikidata: I don’t really see Wikidata being a complete solution as it is not authoritative in of itself. Without authoritative sources Wikidata would be a rather useless source of opinion, rather than fact.
Wikidata, would however be an excellent broker between different identifier systems and provide a much needed way for the community in general to provide additional data to a collection’s record.