You're probably only being exposed to the best and most notable anime, which is giving you a very skewed perspective. In fact every season (anime releases follow a seasonal pattern; Winter, Spring, Summer, Fall) there's tons of same-y and uninteresting trope-filled anime. Most seasonal anime just takes some basic premise as a starting point and then it fills in the rest of the details with tons of tropes, or it copies the key details from other successful entries in the sub-genre. If you started following every anime season you'd quickly notice how many derivative anime are released each season.

You can check it out for yourself, go to anilist.co, and filter for Year 2024, and then filter again for each Season. There's tons of fad-chasing, aside from the major standouts. It's honestly a shame because some of these slop-tier anime still tend to get beautiful animations, but their stories and writing in general is really bad. Sometimes you get an F-tier story with S-tier animation.