A new(?) suggestion for a modern digital mapping feature.

Pete, how about going a bit further and developing a 3D headset so you can just sit at home in absolute safety and travel Oz.
Sorry mate, just kidding.

Quote "but it would seem to be technically possible these days to imbed photographs (and videos?) into digital maps so that as you hover over a spot on a mapped track, a georeferenced (and dated) photo pops up."

You seem to be describing the Google Maps, Street View. When you activate the function, you can click on any of the roadlines that turn blue. You can use the new view to look up or down the road as well as look at the country side. You will get many little round blue circles at popular sites, when you click on one of them you can get pictures on the map pane. Some time you can pan around and zoomto see what is around.

If you search on a town, if there is often a picture that appears where you type the town name is typed into. If you click on that picture it will appear in the map pane. There are forward and back arrows in the bottom centre of the picture where you can view the other pictures if they are available

Have a look at Google Maps - Complete Tutorial for Beginners (for desktop)

In apps like ExplorOz Traveller the map shows overlay icons for places that when tapped show user contributed photos. There are 69,000 such photos in Traveller.

If you are wanting to know what the conditions of a road is like before travelling on it, how is a photo of the road, possibly taken months or even years ago, going to help you assess whether the road is suitable for you to travel on? Also, how is it going to tell you if the road is even open. Nice idea, and perhaps useful from a planning perspective, but not practical in the context of determining what the current road conditions are like.

Macca.