To be fair, it's not an easy series to get into...
sorry but that's where you're wrong.
First, because you think people get into Conan by watching anime lol. Seriously any series with over 500+ manga chapters should never be watched in anime first. ALWAYS read the manga first (for basically every series ever, seriously, who have time for anime nowadays?).
Second, Conan is actually very easy and engaging to read. It has comedy, mystery and murder, all things that children from 8+ loves. There's a reason why anyone from 6 to 40+ in my country has heard of/read Conan at least once. Even my mom (who is 60+) has read/watched a few chapters/episodes of Conan; she doesn't know (nor care) about the entire story but she knows the basic premise and 2-3 stories in Conan.
Anw, while it's true that Conan is stupidly and unnecessarily long, it's not a hard series to get into, it's just hard to follow it through.