A convincing film effect is a relationship, not a single slider.
Grain alone does not make a photograph feel like film. Tone has to leave room in the highlights, color needs a coherent bias, and texture should follow the size of the image. When those decisions disagree, the result looks like several effects stacked on top of one another.
Classic Chrome is a useful neutral reference because its changes are easy to inspect. From there, compare Gold 200 for warmth, Eterna for quieter contrast, or Night Flash for a deliberately rough result. The same photograph reveals what each direction is actually doing.