I finally took all of my courage and implemented (read: copy/pasted with adaptations) something that exists on Wikidata: derived statements.
If you go to geolocation data - PersonalData.IO for instance, you will see a new entry at the bottom of the page that says “show derived statements”. If you click there, you will get the result of a query for all the inverse statements (all the statements pointing to the item you are looking at, rather than from that item).
For geolocation data - PersonalData.IO that would mean you see all the entries that collect this data, collated from the page for each business collecting such data.
This is implemented by adding a statement with predicated “inverse label item” on the property collects - PersonalData.IO. If you look over there, it is actually quite easy for anyone now to start enriching the interface with those inverse links.
This is all implemented through this Gadget, which is activated by default: https://www.wikidata.org/w/index.php?title=MediaWiki:Gadget-relateditems.js