Yeah, I thought so too when I was new here. That was two years ago, and now I have solved quite a few cryptograms in under 10 seconds. My fastest time so far is 7 seconds. My average time is much higher, and some quotes take me over a minute or two -- and some I just give up on -- but I know from experience that you really can solve some of these in just a few seconds.
You'll see, if you keep at it, how the speed picks up little by little. Meanwhile, remember that on this site you don't have to type the whole quote since it has autofill -- you type each letter of the alphabet only once, and I haven't seen a puzzle yet that used more than 24 letters of the alphabet. Most use more like 20 letters, and a fast typist can easily type 20 letters in under 10 seconds. Where the real speed comes in is in recognizing letter patterns, recognizing the quote's author and knowing that author's speech style, and, if you have more brain cells than I do, recognizing the letter patterns of a specific quote you have solved a few times before and then just typing the rest of it from memory. What also helps is having a fast connection: if your computer "hangs" after you submit your solution, that eats up time.
Here is a forum thread that offers YouTube videos of some of your fellow players solving very quickly,
Keep on solving! We look forward to seeing you in the comment box.