This one’s really a no brainer – harem anime.
I even wrote a while back about my distaste of the genre. Long story short, while it’s definitely not meant for me in the first place, harems are some of the laziest shows you can get your hands on. Flat, uninteresting Gary Stu main lead, meet 4-7 insanely beautiful girls you’d have a little to no chance with in real life who fill the criteria of traditional harem characters such as glasses girl, lolicon fodder, childhood friend who is most likely the main love interest, tough and loud chick, and whore.
Gasp and giggle as MC gets himself into all sorts of wacky shenanigans like accidentally groping one of them, accidentally seeing one of them naked, accidentally causing a big misunderstanding that will make main love interest probably punch him and accidentally falling in love because the writers said so.
Let’s not forget the squabbling.
‘He’s my uninteresting male protagonist!’
‘No he’s mine!’
‘Let’s settle this with a boob groping fight in the hot spring!’
…Alright, that’s an exaggeration, but not by much.
I forgot to mention the overly dramatic ones, like H2O or School Days, but that’s a whole different can of worms that still basically works on the same foundation. The same tropes still happen, but they’re surrounded by ultra-drama that is usually capped off with an insane and ridiculous ending.
Not all harems are completely lazy or irredeemable, in fact there are some that are fairly good, but I’ve found that, as a whole, the genre is a minefield of pointless, badly written pandering that I am more than glad to actively avoid.