The regular level influencers are complete nonentities. I remember a story here a while back where an "influencer" with 2 million "followers" couldn't sell 36 T-shirts.
The t-shirt account can't get past 200 comments with 2.6 million followers? Sub-0.001% engagement screams purchased followers - you typically get more than that in spam comments or shoutout-begging alone most of the time I've seen if they are humans...
I am also inclined to believe this even more so due to scrolling through the follower list for under a minute, based off usernames. Another thing is that while scrolling through, some hypermajority appear to be either India, Middle Eastern, or CIS countries, while she has never written a description in any of those - possibly the vendor was also difficult to order from or ship outside of the US or her home country otherwise.
I suspect AI wouldn't even be needed, just harvest real comments from existing high engage feeds and dump them with minor word swaps on to low engage feeds. this alone would probably take a couple years for countermeasures to respond to, assuming there is even an incentive basis to respond at all.