I don't think we need an article to figure out the answer: Slay the Spire was a megahit and it's a copycat industry.
I don't necessarily mean that in a bad way either; there're always plenty of devs finding interesting new angles on the current hot genre and creating genuinely interesting new games in the process, but also a huge number of devs that end up just chasing the trend and releasing something uninspired/derivative.