65mm theoretical is supposedly 14-16K (though analog is never 1:1 with digital and there's more than the size of the negative at play). The Wizard of Oz (Academy ratio film) was scanned at 8K years ago (and we can't really say if a higher resolution scan would help or not as it wasn't attempted and I don't think it has shown in 8K anywhere in theaters) and normal 70mm film is roughly 3.5 times larger than Academy ratio film. If we go by The Wizard of Oz example and theoretically say 8K nabs you a perfect 1:1 scan of 35mm Academy ratio film (which is not proven) and typical 65mm film is 3.5 times larger than Academy ratio film then 14K would nab you 1:1 with 65mm. But the issue is with analog film, the quality of the stock also matters including its' contrast, the silvers in the film itself, the composition of the film, whether it was shot with anamorphic compression onto the film's frame, etc.
Once a tv or tv type image is nearly indistinguishable from real life, that's when we see the upper limits, right now we are far from that realm.