Isobee didn't show growth each volume and it lasted a full 4 years because it performed well in the ToC and added variety. Also Magu's above Undead which just got the cover, sure it's not above any of the 5 main hits but often nothing is.
That's just how jump is right now, you've got the 5 long running hits usually at the top each issue (OP, MHA, Jujutsu, Dr Stone, Black Clover), the mid-tier series that also get colour pages and some of which occasionally get above Black Clover (Yozakura, Mashle, Roboco, Ayakashi, Undead, Magu-chan), the bottom dwellers (Dolphin, HSF, Phantom Seer, Build King), and a bunch of newbies who are either unranked or haven't settled yet in Sakamoto's case.