The files are already compressed using HEVC to maintain the best balance between size and 4K quality. Compressing them further would result in a significant loss of detail.
Moreover, re-encoding and uploading everything requires a lot of time and resources; for context, the files I just shared already took me over 5 hours to process.
If you are looking for smaller, more compressed packs, some are available on the first page of this thread, but I cannot guarantee that they contain all the same content as mine.