That number seems off by a few orders of magnitude.

I tried searching for familiar collections and couldn't find any of them:

- Corruption(*s) - Bored Ape Yacht Club - Lonely Aliens Space Club - NFT Worlds

You also have neither entries for the major Art Blocks series (Curated/Playground/Factory) nor any of the hundreds of individual artist collections contained in them.

So, I think your crawl might be off.

Additionally, individual artists tend to not use OpenSea but instead use Rarible, Foundation, and SuperRare (or skip ethereum altogether and use something on Tezos like fxhash).