One thing missing on osm is pictures. Would defeats Google maps if it had some, where users would feedback and bad shots would get wiped to save space. We would get the best shots the world has to offer.
In the app I'm developing, cartes.app, we acknowledged this lack of pictures.
We show local Wikimedia common pictures, osm tag pictures, og:image pictures of the website if any, Wikipedia article infobox pictures, Panoramax for street-view, and last but not least, any picture dropped by an ATproto place review.
Lots remain to be done, especially building the latter community of reviews.
I had been using mapcomplete to add images of artwork, which in turn used panoramax. However I saw someone else use Wikimedia Commons, and to me that makes more sense. Wikimedia ties into more systems, so if you wanted to create a Wikipedia page about an artist, there will be readily available images to use.
On the flip side, panoramax can be used as an open source StreetView. Different sites for different purposes I suppose
Wikimedia Commons also requires more up-front work by the uploader to categorize the image properly, which can be daunting if you're new to how things are organized there. But yeah, for well-known objects, adding Wikidata and Wikimedia Commons links can be awesome and there are plenty of apps making use of it to show additional information.
Panoramax is still unfortunately very lacking outside a French instance. I've tried to contribute my street view images, but it's not used by anyone or anything as far as I can see.
We show local Wikimedia common pictures, osm tag pictures, og:image pictures of the website if any, Wikipedia article infobox pictures, Panoramax for street-view, and last but not least, any picture dropped by an ATproto place review.
Lots remain to be done, especially building the latter community of reviews.