It seems to be less common this decade. Bokuyaba, Yancha Gal, Komi, Chihara-san, 2nd cutest girl, are obvious examples, but a lot of manga are either doing "They basically confessed and are just waiting on some dumb thing to actually say it"(Nagatoro, will you be my childhood friend), or just having them do a bunch of dating stuff preconfession(Stop! I'm falling for you) so it's fine if it ends on confession.
Additionally a lot of manga are making sure to have a premise that can support itself post confession. Someone Hertz they could confess literally next chapter and still get 100+ chapters of content. Love is War had a fantastic second half where it almost entirely changed premesis
This manga hasn't given itself any legs post confession from what I've seen though, and it's not slice of life enough to just continue floating like komi or chihara since there's currently no side characters other than Ryo and the siblings, or other plot points at all. I suppose since it's likely going throuple it could spend some time exploring the ramifications of that?
