Crackdowns and the biggest pro scan group sites getting neutered or nuked during kakao's copyright rampage.
When places like Kakao forget they even have an English and other foreign markets to sell to thanks to author-first translators, they uproot the ones who point readers to their legal sites and leave the scene flooded with Desire, et al. types who would normally never get their slop uploaded on aggs but their own.
Japan made the same mistake back in the day and it did nothing but birth worse aggregator sites they couldn't touch.

When u show up in an annoying contest but the big 3 ai scanlation team show up :(