What do you mean by “get”? I have an Epson V700. I have done plenty of side by side comparisons. The sharpness of the grain in the scan is what matters, not merely “getting” the grain. To speak of the resolution of a film exposure is incoherent. Grain != pixels. The V700 is also inconsistent because of the floppy plastic mounts and because they lack a mechanism to really keep the film flat.
If you can see individual grains you are already limited by the film itself, anything beyond that is noise. Sharper grain is just a higher spatial frequency noise.
Because Epson scanners don't actually resolve the grain. Low resolution scans tend to exaggerate grain... which can make you think you're resolving the grain.
Also, photos aren't only about resolution and sharpness. Colour and tone reproduction is also important. And consumer scanners are acceptable, but nowhere near as good as drum scanners. Even minilab scanners (Fuji Frontier, Noritsu) are no match for drum scanners.
It can't. It really can't. Even with betterscanning.com holders you can't beat dedicated film scanners or dlsr scans. Drum-scan obviously being the best. I've never wet mounted on flatbeds so can't comment.
My almost 2decades old Nikon V-ED, which I bought when it came out, still outperforms the most expensive flatbed you can buy now (V850-pro), which I also have.