Basically every wikipedia page (across languages) is linked to wikidata, and some infoboxes are generated directly from wikidata, so they're seperate, but overlapping and increasingly so.
I agree there is strong overlap between entities, and also infobox values, but both wikidata and wikipedia has many more disjoint datapoints: many tables, factual statements in wikipedia which are not in wikidata, and many statements in wikidata which are not in wikipedia.
https://en.wikipedia.org/wiki/Category:Articles_with_infobox...
edit: slightly wider scope category pointing to pages using wikidata in different ways:
https://en.wikipedia.org/wiki/Category:Wikipedia_categories_...