Hey there @mighty_chebo
You are correct, I will make a note to update this documentation for v11.
v11 significantly changes the way that databases work in Foundry, no longer using NeDB .db files but rather LevelDB folders which contain the database.
On Windows, explorer does not show folder sizes because it can be slow, so unfortunately you would need to r-click → properties to check each individual folder. Optionally, I also like to use a tool called WinDirStat, pictured here:
Much of the same logic applies as with before v11:
World compendiums (/packs folder) and the fog database still aren’t loaded on the first world loading step, and if you experience slow loading, you may want to archive some of your unused actors, scenes or items to a shared compendium.
However, database corruption and the long repeats that could sometimes happen in NeDB should no longer be a problem in v11, so there should be no need to unpack the databases to read/fix the data inside.
Note:
For developers and content creators who have a reason to want to edit the DB files directly, I recommend looking into GitHub - foundryvtt/foundryvtt-cli: The official Foundry VTT CLI which allows the unpacking to JSON and re-packing to LevelDB 