Not all sequel manga/anime are bad but they need to do a damn fine job of expelling the old generation and their OP powers that they acquired near the end of their original storylines. Super is bad because Toriyama doesn't remember shit and frankly is traumatized from having to work on Slump and Dragon Ball with only less than 6 months of hiatus in between (and most of it was spent gathering research and concept materials for DB) for 15 years. He simply doesn't give enough of a fuck about Super's storyline to do much more than panel corrections for Toyotaro and as for the anime, it's pretty much a rule of cool Bleach meets Dragon Ball at this point - good for spectacles like in the late ToP or episodes 57 and 66, but not good for much else.
Boruto is terrible because Kishimoto was just a shit writer to begin with and had no talent, and the only reasons Naruto took off was due to him at least writing Part 1 Naruto convincingly (based on his own experiences as a kid who got bullied for being a recluse with horrible grades who did nothing but draw in a corner), and the editorial board helping him immensely by not making Kakashi a ripoff character of Himura Kenshin, by cutting down on the type of annoying Hunter x Hunter style exposition for every technique and so on - and even then the manga went completely down the shitter after Jiraiya's death/after the Pain arc at the latest. His Samurai 8 manga was an absolute flop too, and showed what an unsupervised Kishimoto can't help but create
One Piece is without a doubt getting a sequel series after it ends due to its popularity, I just hope that Oda has more participation in it and he has a competent artist who understands his work better than Toyotaro understands Dragon Ball. Kubo is apparently doing a sequel manga himself similar to Watsuki doing Kenshin Hokkaido-hen, but I ain't touching that or Boruto with a 10 foot pole
At this point I would prefer a Slam Dunk or Yu Yu Hakusho continuation. Just make a miniseries centered around the Shohoku HS Basketball Team's endeavors against Kainan, Shoyo and Ryonan in the Winter Qualifying championships, running side to side with Sakuragi's rehabilitation with him joining in whoever is Shohoku's final opponent - perhaps as Rukawa's stand-in when he is defeated against Sendoh. Yu Yu Hakusho was always asspull after asspull after Toguro's death so spinoffs probably won't ruin it and Togashit obviously has no motivation to continue HxH anyway, he can probably do the story with someone else doing the art (and probably far better than his usual scribbles a la Greed Island's last chapters, half of the Chimera Ant arc).
