Quick, who uses a dictionary more? a) smart people; b) people who . . . aren’t so smart.
Notice that that’s a different question than, “who should use a dictionary more . . . ?”
Given how ridiculously easy it is to look up a word online, there’s no reason every serious reader today doesn’t bookmark a couple reference sites (Webster’s, an online thesaurus, etc.), plus Wikipedia.
P.S.: The first book I read?
The “C” encyclepdia when I was a kid, just out of curiousity (I then moved on to “M” and “P” before losing interest).