and before anyone brings up the newest mainline Karami Zakari issue released earlier this year, where Katsura Airi decided to have Kousei finally move on from Iida and marry another girl, in the very same story Kousei still entertains a final cuckold fantasy with Iida as she lays down with others before going through his marriage at the end.
So even when a protagonist in a Katsura Airi work gets an unexpected positive development, he still got one last humiliation ritual as par of the course.
People like to read Kousei moving on as Iida ending as the miserable leftover from their group of friends, as Takeshi got rewarded with a successful career as a fuccboi photographer who fucks all models, despite being the first guy who NTR'd Kousei, and Niiyama got rescued from living as a slut by a charming childhood friend prince that married her, despite she being almost as loose as Iida, but Niiyama is loyal when she has an actual official boyfriend so she got a pass for getting a happy end.
But if Katsura Airi doesn’t write Iida regretting her life choices then it really only remains as the audience interpreting she looking at Kousei's wedding pic as some sort of longing regret.
Here, in GraPara! Sakura's career immediately soared after leaving Shinobu behind, and she broke up with him through text! That's a trademark Katsura Airi rewarding her female leads for their actions.
So yeah, keep your expectations low till the series ends, or all major developments unfold.