Note, this stuff is so dumb but affects mempools.
For about a week, the amount of brc-20s went down greatly. Brc-20s, unlike the jpegs don't stretch blocks. When this happened, it allowed the stretching of the jpegs to go unencumbered raising the avg block size. (Until, they came back.) Brcs also caused the massive fee spike. The date of the spike is circled. See how the avg block size shrank in the middle of blocks being 90% inscriptions? That's brc20s.

https://image.nostr.build/9be1586aae8b16a640dc354231d37db6e18041d241997212f46e82a5e0912ebb.jpg

https://image.nostr.build/872e9d56b72f6bd48edd6c4444db01117e746d74d775c1fb51df26e2a645da24.jpg