It's a good idea to create a more decentralized solution to share your parkour spots.
Unfortunately osm.org does not support custom POI lists.
The german OSM community is hosting a Umap service, where you could create a custom POI map. (https://umap.openstreetmap.de/en/)
The map can then be shared and the POIs can be downloaded as gpx, kml or similar file. This file can then be imported into any Map Apps.
For the photos.. If you get the permission to put these under a Creative Commons License, then you can upload them to Wikimedia. Then put the link into the description of the POIs in the Umap
The map tiles are greyed out and have less contrast then before. Unfortunately there is also no switch setting for normal mode.
Now I use the Mozilla Dark Reader Addon to increase contrast again. Makes the experience of osm.org in dark mode much better.