Even in so called sandbox games repetition isn't necessary, it just gives the illusion of doing something while waiting for the next update. Of course people also
want some stuff to be repeatable, espesiclly the lewd stuff ('how can I unlock the gallery?'), but it's not a prequisite.
MotH started with stats first, then got completely changed to a pure event based game. Yes, there were progress stars, they inidicated how much many of the events you already had seen, and that unlocked certain actions or other events, so basically it was a 'relationship level'. But there was no stat grinding (except that you had to deliver pizza for money) and no decay.
House Party has stats, but those basically only mean that you can fuck up completely and block your way with a girl. All the content is implemented like in an adventure.
The first AIF games I played were actually text adventures, most of them without any game relevant stats (In 'Moist' you could get the girls horny so they would basically jump you or you could 'convince' them). Since there were no images to render, all development time went into story and lewd scenes descriptions.
Those games were much more daring than the modern visual novels, as writer you could get away with everything
Who hasn't played them yet and has a tiny rest of immagination left in his multimedia fileld brain should try them. But be aware, back then no one cared if there's NTR in the game or incest or whatever, no patreons who decided what the next updated was gonna be about. There was just the story. In one guy you play a female spy who uses both skills and body assets to get what she wants. In Sam Shooter the MC was the guy spreading his genes worldwide, but later in the series he got to share his sister with others on several occasions and at some point she would cause a distraction by banging a group of cops.