Hi!
I think Wikipedia really needs a central bibliography, because there are many books who are used in more than one article, some in dozens or even more.
Can't do that unless you use some form of wikidata. It makes little sense to reinvent filesystems based on templates when dbs are used for that stuff some 20 years already. The smarter solution would be to use ISBN code in the actual wiki version, hacking the "find books" function to reach an external repository based on wikidata. At that point you could also trace the quotations coming in from the main wiki and build cross-reference tables, relevance of authors per subject... that is, you'd have a real bibliography.
But it makes sense to keep this thing external, as most users are not going to need it and it would add overtime during execution.
Bèrto