What makes a time loop story compelling?

Compelling to you personally, of course.

I love time loops. Groundhog Day, Russian Doll, give me all of that. But now that I'm working on a time loop story, I find myself constantly questioning how to make a single day repeated over and over compelling.

The obvious answers are:

1) make the original day in itself interesting 2) make enough changes to the following loops to keep it new

But I'm curious what people think because I can't exactly put a finger on why I find time loop interesting myself.