>>1545377 (OP)
desuarchive has image repost stats for individual boards, but I can't find them for all boards collated together.
There is no site that archives every single 4chan board, and certainly no archive that started archiving every board at the same time.
Out of boredom, I did look through every board to see which board's #1 reposted image was reposted the most. It was /int/
https://desuarchive.org/int/statistics/image-reposts/
/r9k/ was second
https://desuarchive.org/r9k/statistics/image-reposts/
