I've got a (relatively old) snapshot of the English Wikipedia that I'm using for testing. The snapshot is around 200 GiB in 14,000,000 files and compresses down to an 11 GiB DwarFS image.
would maybe a database dump be smaller?
>As of May 2015, the current version of the English Wikipedia article / template / redirect text was about 51 GB uncompressed in XML format.
Compressed data at the same time was 11.5 GB. And that's data from 9 years ago, and just English Wikipedia.
For comparison, I collect leaked password dumps and they (combined, after deduplication) go into hundreds of GBs too. And that's for just username:password lines, not even text.