You have to remember that APIs were used massively by third party apps users.
I don't see a reason to attribute the API related drop more to automation than users stopping browsing reddit because third party app ban.
We have known for more than a decade now that training machine learning models on huge user data sets allows to predict a lot of things with decent accuracy.
Twitter has been gathering a lot of data on all of its user, it is expected them to be able to predict interests like (and much more) this if you use their service.
No need to spy on your smartphone beside what you submit willingly https://hbr.org/2012/09/use-big-data-to-predict-your-c
As they say, from number 2 army in the world to number 2 army in Ukraine.
Now with a risk of becoming number 2 army in Russia...
This is where I have been finding anything I really need to torrent.
I stopped for a couple of years during the peak of kickass torrent, when I came back TPB had moved to an onion domain but it seems the quality is higher than in the 2010s.