I have traveled quite a bit and taken a lot of photos (with gps data). Ideally I would like to use these photos to create a map connecting the different waypoints via roads which I could then use in a slideshow. Bonus points if the map can be animated with panning and zooming effects for different parts of the journey.
Darktable? It's a RAW developer and photo managing software on Linux, Windows and Mac, a little bit like Adobe Lightroom, but OpenSource. If GPS coordinates are in the RAW, sidecar or jpg files, the photos can be displayed in the map module. Much better, if you have a GPX file and no GPS data embedded, you can assign the photos to the GPX route, as long the timestamp of DateTimeOriginal in Exif is accurate. If the timestamp differs, you can specify the difference.
Maybe Digikam can do the same. But I don't like the KDE framework which is used there. Digikam is available for Linux and Windows (yes, I know it's strange).
Okay so it's very much not FOSS (we're talking upwards of a couple hundred $ / month) but Esri's StoryMap feature through their ArcGIS software suite would allow you to do exactly this. Having used StoryMaps though, this is by far the most comprehensive way to do something of this nature. You can upload GPS data directly to the software, export the map to the ArcGIS Online suite, then create a storymap from there. StoryMaps can be panned, animated, zoomed etc to your heart's content.
Your other solution would be with QGIS, which is FOSS. I don't think they have a StoryMaps analogue, but I've heard "QGIS2WEB" sort of works like that.