Very often i have mapped art objects in public space in Bern with relation instead of a much more simple knot or way. Reason is, that all objects have Wikidata ID and pics in Wikimedia. My intention was, that I wanted the OSM ID of the artwork to get displayed with active link in Wikimedia. Therefore I had to add OSM ID in Wikidata (Identifiers OpenStreetMap relation ID), only "coordinate location" is "nice to see" but adds no benefit for web users. So, OSM relations provide this benefit, but OSM ways or knots don't.
Links:
https://umap.osm.ch/de/map/public-art-in-bern_2444
https://commons.wikimedia.org/wiki/Category:Public_art_in_Bern
