I think one component of it is the devaluing of writing in the industry. A big issue in the most recent WGA strike (mostly glossed over in favor of obsessing over the AI stuff) was studios pushing really hard to turn writing into one-off gig work instead of a stable position. A lot of successful shows have a first season that is lackluster or just plain "off" because they hadn't figured out what the show was actually about, and I suspect that excessive commoditization of the writing process is a recipe for producing that "weird first season" every season.