Because those are two different situations? In Noa's case, the lack of romantic progress is purely dictated by an author's will (or rather lack of thereof), even tho the characters are basically behaving like they are dating. Plus in Noa almost every chapter is based on her being clingy and annoying. In this manga, characters at least have reasons to behave like that - Mikoto was bullied in middle school to the point, her face was splashed with an acid. She has scar for life. She has real reason to have little to none faith in herself. And she's a kid, not 30 y/o adult. Takase is also a kid, who's punishing himself for abandoning Mikoto's side. Unlike Rihito, who's just... Boring and unrealistic atp. And they at least realize they have feelings for each other, unlike those so called "adults" in Noa.