OSM's success has largely come from being efficient and focused. Adding photos and Street View would move into areas where the project has no expertise.

For navigation, on the other hand, it's already streets ahead (pun unintentional) of Google et al... for those of us who travel on foot or bike, that is!

There's https://openstreetcam.org/ and https://www.mapillary.com/ for anybody who want to contribute. It's a huge operational cost to run such a service for free. OSM doesn't run donation campaigns like wikipedia/wikimedia does.

No, OSM should focus on what it is and what it does well. Reviews and photos are bound to attract a lot of garbage and problems. Navigation sure, there is lots of that available on OSM data already. Street view is also already covered by mapilliary and openstreetcam.