The two games that do this are Far Cry 5 and Forza Horizon 3. I realize movign it all around would probably require to rewrite most of the disk, but I don't think that should be a problem given it doesn't happen every day, or even every month.

No system files save for pagefile and a couple of installed programs. This is on a disk that is pretty much data only: movies, photos, music, game files, documents etc. Are they shitty tools? Do I need some before-OS-loads tool? Is this not possible for some reason? If this is a somewhat accurate representation fo the situation, I don't understand why the programs leave it at that, instead of moving all those blue/green blocks of data closer together to create larger stretches of empty blocks. Grey squares are empty blocks, red squares are fragmented files. But I expected that the tools would do exactly that, create a contiguous space for large files. It currently reports around 7% fragmented and running further jobs changes nothing, I suspect because the fragmented files are in the 5-20GB range and without movign stuff around there just isn't that kind of contiguous space. I've run 3 different defrag tools (Windows 10, Auslogics DD and Smart Defrag 6), and every time I end up with an unfinished job, see the screenshot.