This argument works just as well for exponential decay: it’s “always the wrong model” because no decay lasts forever, eventually you’ll run out of atoms in your radioactive sample (or whatever else you’re modeling), and so some other curve that intercepts the y-axis in finite time is a better model because it gets the “basic shape” right and doesn’t make “an extremely obvious mistake when modeling reality.”
This argument works just as well for exponential decay: it’s “always the wrong model” because no decay lasts forever, eventually you’ll run out of atoms in your radioactive sample (or whatever else you’re modeling), and so some other curve that intercepts the y-axis in finite time is a better model because it gets the “basic shape” right and doesn’t make “an extremely obvious mistake when modeling reality.”