Seto is denser than a black hole, but Anjou makes up for it by just how good she is. It’s like if Nagatoro was amped up and went full send. Anjou is fully committed and doesn’t have a “tsundere” blush, she’d accept all the consequences.
Senpai is much better than Seto, though, Seto takes the “relatable” parts of Senpai and amps them up too, which turns Seto into an annoying dense protag. However, I don’t think it’ll be for forever, after 77 chapters there’s the tiniest bit of development. The pace is sooo slow though.