My obsidian vault has passed the sync limit of 10 GB, even though through the viewfinder, it is only 830 MB large. I contacted obsidian sync support, where it was determined that Excalidraw saves a lot of snapshots very quickly. Changing the snapshot interval within Excalidraw helps, but the developer said:
Allow for deleting of file histories. This would allow keeping the current version of the files (and excalidraw files), but without the option to undo. That way, you can clear history of the files you don’t need the history for, saving a lot of space and allowing usage of the vault for longer periods of time.
I have to create a new vault and copy all my files over. Clearly not optimal.