This is in fact one of the primary points of TFA and the book it recommends: that the degradation of literacy, public discourse, and general intelligence that started with the television (and was well-described in Amusing Ourselves to Death, referenced in TFA, and which the title pays homage to) has only continued and, if anything, accelerated with the introduction of the smartphone and modern social media.

The average children's cartoon from the early 2000s has several orders of magnitude more value than the average tiktok feed.

The existence of slop in the 90s doesn't prove that slop is not more prominent in the 2020s.