I don't think that many people use LaTeX on their resume as a way to look impressive just because they know LaTeX. I think that many people use it because they find that it easier to control the layout of their document than in something like MS Word or {Libre,Open}Office Writer. I spent a number of years with a MS Word resume filled with tables to space things out correctly. I used to dread needing to make changes to it because of how fragile the setup was. On the other hand, I find it relatively easy to make changes to my resume now that I have it in LaTeX.