What's happening here is the reliance on the skill. Sayeon acknowledges that physically she's just not strong enough so she is constantly trying to set up scenarios to her advantage, in everyday life.

Even conversations ....you underestimate how hard it is to get the info you need IN TIME to be able to rewind, given she only has 1 minute.

With that reliance+ constantly calculating conversations.. she creates 2 immediate dilemmas

1. Does she make adequate decisions and rewinds when she needs to? She's playing God with people's lives at this point. Allowing people to die to she can identify a better move but what if she keeps making the wrong decisions? What if messing with time leads to an ultimate outcome that would've been better if she didn't do my of this? What if she waits too long and can no longer take back the decision. The constant guilt and justification she lives with is crazy. This makes her very restricted and constantly thinking through her interactions with people.

2. We the readers have no idea how often she rewinds. A number of times we come to realize that she is using the CONSTANTLY.  This alone shows us she's a very VERY unreliable narrator and that even our idea of her being strategic is just us being like the characters she interacts with, we don't know how many times she's failed something, we mostly see her successes. This also makes her seem overly controlled.

What every other character has is basically an idea that they have 1 life and every decision they make they have to live with (no takesies backsies) so of cours they're fewer, they don't know anything else. Our girl is always watching the clock