There's no 1:1 for film into digital in terms of resolution, especially since most scanners at 2K resolutions 10-15 years back can't compare to 2K scanners today, so resolution is just one piece of the puzzle. It's an analog to digital conversion, which will always be lossy. Upgrades in tech keep proving talking heads wrong about the scanning of certain formats. They used to say 16mm film wouldn't benefit from 4K scans but then they started scanning The Texas Chain Saw Massacre, The Evil Dead, old John Waters films, etc. in 4K and they looked much better than the old 2k and 1920x1080 scans. There's also the case of cinematographic techniques that can subtract or be used to better visual quality that can effect what info can be gleaned via scanning.
There are also all sorts of film formats from 8mm (usually home movies and student films that cannot afford 16mm) to Ultra Panavision (which benefited from essentially compressing an image 1.25x larger than 65mm film onto the film's negative), Imax (which is the largest film single negative used in commercial/non-experimental movies), and Cinerama (three 1.33:1 negatives shot side by side and projected as if it were one image), so the visual information to be gleaned from each differs. On top of that the quality of the film used varies a lot. They have film negative with much finer particles of silver and higher quality makeup than old acetate film (old nitrate film from the late 10's to 20's though can super lifelike due to the higher contrast, different properties of the nitrate and how they used silver in film at the time).